RESEARCH Open Access Decapod crustaceans associated with macroinvertebrates in Pacific Costa Rica Carolina Salas-Moya1,2* , Rita Vargas-Castillo3 , Juan José Alvarado1,2,3 , Juan Carlos Azofeifa-Solano1 and Jorge Cortés1,2,3* Abstract Decapod crustaceans are a diverse group that exploits various types of habitats in Costa Rica, where they represent 8.1% of the marine diversity of the country. This group includes families containing species with strictly symbiotic behavior, e.g., the Palaemonidae and Pinnotheridae. Despite the high diversity of decapods and the importance of symbionts in marine ecosystems, very little research has been done regarding symbiosis in Costa Rica and the Central American region. The objective of the present study is to present a check list of the species of decapods that are associated with macroinvertebrates in Pacific Costa Rica. The research was carried out using different sources, including a literature review, the Crustaceans Collection of the Zoology Museum of the University of Costa Rica, and field surveys between 1970 and 2019 along the Pacific coast of Costa Rica, and Isla del Coco, 500 km offshore. One-hundred associations are reported, of 74 species of symbiotic decapods with six host phyla. Seventy- four associated with Cnidaria, 15 with Echinodermata, four each with Annelida and Mollusca, two with Chordata, and one with Porifera. In total, there were 14 new reports of decapods occurring on Isla del Coco and four new reports of decapods for Costa Rica: Pseudocoutierea elegans, Raytheres clavapedatus, Tuleariocaris holthuisi, and Calyptraeotheres pepeluisi. These results highlight the need to conduct more detailed studies to determine the real diversity and ecological importance of the associations between marine organisms. Keywords: Isla del Coco, Coral reefs, Biodiversity, Palaemonidae, Pinnotheridae, Symbiosis Introduction The diversity of decapod crustaceans is directly corre- lated with the abundance of habitats exploited by these organisms, including continental waters, intertidal zones, coral reefs, the deep sea and even the body cavities of other marine organisms (Bruce 1976; Martin and Davis 2001; Macedo et al. 2012; Sal Moyano et al. 2012; Baeza 2015). The different species expend a great deal of en- ergy in habitat selection because the location that they choose should not only allow them to survive, but also to reproduce (Anthony and Cannolly 2004). In their search for shelter, many of these animals are exposed to the presence of spatially and temporarily limited resources. Some of these resources include aggregations of seastars, sea urchins, mussels, algal mats, and kelp forests, among others (Baeza et al. 2002; Ory et al. 2013). The characteristics of the habitat, predation and interspecific competition encourage great specificity of habitat selection and are even considered to be drivers of symbiotic relationships (Montfrans et al. 2003; Baeza 2007; Ory et al. 2013). Symbiosis is a very common type of interaction in marine ecosystems (Thiel and Baeza 2001; Sotka 2005; Baeza 2007; Glynn 2013). It has been defined as “the living together of unlike organisms” (De Bary 1879). Other definitions include the factor of time, since these associations can extend through a part or the entirety of the lifecycle of one or both organisms (Starr et al. 2009). In Costa Rica, there are 591 species of decapods, 8.1% of the known marine biodiversity of the country © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. * Correspondence: carosalasm@gmail.com; jorge.cortes@ucr.ac.cr 1Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José 11051-2060, Costa Rica Full list of author information is available at the end of the article Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 https://doi.org/10.1186/s41200-020-00199-w http://crossmark.crossref.org/dialog/?doi=10.1186/s41200-020-00199-w&domain=pdf https://orcid.org/0000-0002-3781-8127 https://orcid.org/0000-0003-0561-2121 https://orcid.org/0000-0002-2620-9115 https://orcid.org/0000-0002-2105-1056 http://orcid.org/0000-0001-7004-8649 http://creativecommons.org/licenses/by/4.0/ mailto:carosalasm@gmail.com mailto:jorge.cortes@ucr.ac.cr in both oceans (Vargas and Wehrtmann 2009; Wehrt- mann et al. 2009). The families in this group with the greatest species richness in Pacific Costa Rica are Xanthidae (45 spp.), Porcellanidae (44 spp.), Majidae (43 spp.), Alpheidae (34 spp.), Ocypodidae (28 spp.) and Palaemonidae (23 spp.) (Vargas and Wehrtmann 2009). Similarly, of the 1688 marine species reported for Isla del Coco, 8.2% are decapods (Cortés 2012). Some decapod species are adapted for symbiotic be- havior. Among the most well-known groups for estab- lishing associations with other species are the families Palaemonidae, Alpheidae, Pinnotheridae and Porcella- nidae (Baeza 2007). The decapods that live in associ- ation with other animals in Costa Rica have been scarcely studied and in most publications they are only mentioned in species lists with no indication of their association with other organisms. The objective of the present study is to present a compilation of species of decapod crustaceans associated with macro- invertebrates in the Pacific of Costa Rica. Materials and methods Study sites This study includes specimens collected in different lo- cations, associated with different biological substrates, along the Pacific coast of Costa Rica, including from the north, Bahía Salinas and Gulf of Papagayo; to the Central Pacific coast: Gulf of Nicoya; and to the south: Golfo Dulce; as well as different sites around Isla del Coco National Park (Fig. 1, Table 1). These sites have different levels of protection and the health status of their ecosys- tems differs considerably (Cortés 2016a, b). Locations along the northern coast (Bahía Salinas, Bahía Cuajiniquil, Islas Murciélago and Bahía Culebra) are under the influence of a seasonal coastal upwelling (McCreary et al. 1989; Alfaro et al. 2012). The coral ecosystems in Bahía Cuajiniquil in the Gulf of Santa Elena are dominated by the genus Pocillopora, and the species Porites panamen- sis and Pavona gigantea, while the reefs in Bahía Salinas are basically made up of P. gigantea (Cortés et al. 2010). In the reefs of Bahía Culebra, coral cover is under 1%; this ecosys- Fig. 1 Collection sites mentioned in the text and Tables Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 2 of 13 Table 1 Hosts, associated decapods, sites, depth and year of collections Host Phylum Host Group Host Species Associated species Site Abundance Depth (m) Year Porifera Demospongidae Halichondria sp. Panopeus chilensis Punta Morales, Golfo de Nicoya, Puntarenas Abundant Intertidal 2014 Cnidaria Scleractinia Pavona gigantea Opecarcinus crescentus Isla del Caño, Puntarenas Abundant 6 1992 Pavona gigantea Opecarcinus crescentus Islas Pelonas, Bahía Culebra, Guanacaste Abundant 16 1992 Pavona gigantea Opecarcinus crescentus Playa Pochote, Guanacaste Abundant NI 1994 Pocillopora damicornis Ala cornuta Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora damicornis Alpheus lottini Islas Palmitas, Bahía Huevo, Guanacaste Abundant 6–10 1997 Pocillopora damicornis Alpheus lottini Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Amphithrax tuberculatus Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora damicornis Cycloxanthops vittatus Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora damicornis Fennera chacei Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Hapalocarcinus marsupialis Islas Palmitas, Bahía Huevo, Guanacaste Rare 6 1991 Pocillopora damicornis Harpiliopsis depressa Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Heteractaea lunata Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Pachycheles biocellatus Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Pagurus lepidus Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora damicornis Petrolisthes haigae Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Teleophrys cristulipes Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Trapezia bidentata Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Trapezia corallina Playa Blanca, Bahía Culebra, Guanacaste Abundant 3 2003–2004 Pocillopora damicornis Trizopagurus magnificus Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora damicornis Williamstimpsonia stimpsoni Playa Blanca, Bahía Culebra, Guanacaste Rare 3 2003–2004 Pocillopora sp. Alpheus lottini Bahía Thomas, Cuajiniquil, Guanacaste Abundant 2 2016 Pocillopora sp. Brachycarpus biunguiculatus Bahía Thomas, Cuajiniquil, Guanacaste Abundant 2 2016 Pocillopora sp. Domecia hispida Bahía Santa Elena, Guanacaste Rare NI 1994 Pocillopora sp. Hapalocarcinus marsupialis Isla del Caño, Puntarenas Rare 8–10 1986 Pocillopora sp. Harpiliopsis depressa Bahía Santa Elena, Guanacaste Abundant NI 1994 Pocillopora sp. Hemus finneganae Playa Matapalo, Guanacaste Very abundant 6–14 2008 Pocillopora sp. Lipaesthesius leeanus Playa Matapalo, Guanacaste Rare 6–14 2008 Pocillopora sp. Stenorhynchus debilis Playa Matapalo, Guanacaste Very abundant 6–14 2008 Pocillopora sp. Trapezia bidentata Bahía Thomas, Cuajiniquil, Guanacaste Abundant 2 2016 Pocillopora sp. Trapezia cymodoce Bahía Santa Elena, Guanacaste Abundant NI 1994 Porites lobata Alpheus floridanus Parque Nacional Isla del Coco Rare NI 2004 Porites lobata Pachygrapsus transversus Parque Nacional Isla del Coco Very abundant NI 2004 Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 3 of 13 Table 1 Hosts, associated decapods, sites, depth and year of collections (Continued) Host Phylum Host Group Host Species Associated species Site Abundance Depth (m) Year Porites lobata Paracallianidea laevicauda Parque Nacional Isla del Coco Rare NI 2004 Porites lobata Parapinnixa cortesi Chatham Bay, Parque Nacional Isla del Coco Rare NI 2004 Porites lobata Petrolisthes artifrons Parque Nacional Isla del Coco Rare NI 2004 Porites lobata Uca (Petruca) panamensis Parque Nacional Isla del Coco Rare NI 2004 Porites lobata Pomatogebia rugosa Parque Nacional Isla del Coco Abundant NI 1988–1989 Tubastraea coccinea Platypodiella rotundata Isla San José, Islas Murciélago, Guanacaste Abundant 30 2010 Antipatharia Antipathes sp. Periclimenes murcielagensis San Pedrito, Islas Murciélago, Guanacaste Rare 25 1996 Antipathes sp. Waldola schmitti San Pedrito, Islas Murciélago, Guanacaste Rare 25 1996 Lillipathes ritamariae Coralaxius galapagensis Parrita, Puntarenas Rare 1000 2009 Myriopathes panamensis Eupilumnus xantusii Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Gnathophyllum panamense Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Iridopagurus occidentalis Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Lipkemedaeus spinulifer Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Pachycheles velerae Everest, Parque Nacional Isla del Coco Abundant 70–80 2009 Myriopathes panamensis Periclimenes murcielagensis Peñon Abrazo de la Muerte, Islas Murciélago, Guanacaste Rare 30 1999 Myriopathes panamensis Pilumnus stimpsonii Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Quadrella nitida Peñon Abrazo de la Muerte, Islas Murciélago, Guanacaste Rare 30 1999 Myriopathes panamensis Stenorhynchus debilis Everest, Parque Nacional Isla del Coco Abundant 70–80 2009 Myriopathes panamensis Synalpheus sp. Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Myriopathes panamensis Veleronia sympathes Everest, Parque Nacional Isla del Coco Abundant 70–80 2009 Myriopathes panamensis Waldola schmitti Peñon Abrazo de la Muerte, Islas Murciélago, Guanacaste Rare 30 1999 Octocorallia Eugorgia mutabilis Megalobrachium tuberculipes Los Potreros, Puerto Jiménez, Puntarenas Abundant Intertidal 2013 Eugorgia mutabilis Neopontonides henryvonprahli Los Potreros, Puerto Jiménez, Puntarenas Rare 11 2013 Eugorgia mutabilis Orthochela pumila Los Potreros, Puerto Jiménez, Puntarenas Rare Intertidal 2013 Eugorgia mutabilis Pseudoveleronia laevifrons Los Potreros, Puerto Jiménez, Puntarenas Abundant Intertidal 2013 Eugorgia mutabilis Typton sp. Los Potreros, Puerto Jiménez, Puntarenas Rare 11 2013 Leptogorgia cortesi Hippolyte sp. Punta Islotes, Golfo Dulce, Puntarenas Rare NI 1997 Leptogorgia cortesi Periclimenes infraspinis Punta Islotes, Golfo Dulce, Puntarenas Rare NI 1997 Leptogorgia cortesi Periclimenes sp. Punta Islotes, Golfo Dulce, Puntarenas Rare NI 1997 Leptogorgia cuspidata Raytheres clavapedathus San Pedrito, Islas Murciélago, Guanacaste Rare NI 1994 Muricea sp. Pseudocoutierea elegans Everest, Parque Nacional Isla del Coco Abundant 70–80 2009 Muricea sp. Quadrella nitida Everest, Parque Nacional Isla del Coco Rare 70–80 2009 Muricea sp. Quadrella nitida Rodolitos, Parque Nacional Isla del Coco Rare 50 2009 Pacifigorgia irene Megalobrachium Playa Matapalo, Península de Osa, Puntarenas Rare 11 2013 Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 4 of 13 Table 1 Hosts, associated decapods, sites, depth and year of collections (Continued) Host Phylum Host Group Host Species Associated species Site Abundance Depth (m) Year tuberculipes Pacifigorgia irene Neopontonides henryvonprahli Playa Matapalo, Península de Osa, Puntarenas Rare 11 2013 Pacifigorgia irene Orthochela pumila Playa Matapalo, Península de Osa, Puntarenas Rare 11 2013 Pacifigorgia irene Pseudoveleronia laevifrons Playa Matapalo, Península de Osa, Puntarenas Rare 11 2013 NI Nemausa sinensis Dos Amigos, Parque Nacional Isla del Coco Rare NI 2001 NI Neopontonides henryvonprahli Islas Palmitas, Bahía Huevo, Guanacaste Rare NI 1997 NI Pseudoveleronia laevifrons Sámara, Guanacaste Rare NI 1997 NI Pseudoveleronia laevifrons Dos Amigos, Parque Nacional Isla del Coco Rare NI 2001 NI Quadrella nitida Dos Amigos, Parque Nacional Isla del Coco Rare NI 2001 NI Veleronia serratifrons Bahía Salinas, Guanacaste Rare NI 1997 Pennatulacea Euceramus transversilineatus Punta Sortija, Bahía Santa Elena, Guanacaste Rare NI 2013 Hydrozoa Stylaster marenzelleri Munida sp. Everest, Parque Nacional Isla del Coco Rare 86 2014 Stylaster marenzelleri Pseudocoutierea elegans Everest, Parque Nacional Isla del Coco Abundant 86 2014 Mollusca Gastropoda Crepidula sp. Calyptraeotheres pepeluisi Punta Morales, Golfo de Nicoya, Puntarenas Rare Intertidal 2014–2016 Bivalvia Pinctada mazatlanica Pontonia margarita Isla Tortuga, Golfo de Nicoya, Puntarenas Rare 2–18 1993–2018 Pinctada mazatlanica Pontonia margarita Parque Nacional Isla del Coco Rare 8 2014 Pinna rugosa Pontonia simplex Playa Iguanita, Bahía Culebra, Guanacaste Very rare NI 1995 Sacosstrea palmula Austinotheres angelicus Punta Morales, Golfo de Nicoya, Puntarenas Very abundant Intertidal 2012–2014 Annelida Polychaeta Lanicola sp. Glassella costaricana Punta Morales, Golfo de Nicoya, Puntarenas Abundant Intertidal 1992 NI Tetrias scabripes Bajo Manuelita, Parque Nacional Isla del Coco Rare 66 2009 Onuphidae Pinnixa longipes Punta Islotes, Golfo Dulce, Puntarenas Rare 10 2014 Onuphidae Polyonyx nitidus Punta Islotes, Golfo Dulce, Puntarenas Rare 10 2014 Echinodermata Asteroidea Asteropsis carinifera Calyptraeotheres sp. Bahía Culebra, Guanacaste Rare 12 2014–2016 Asteropsis carinifera Pachycheles biocellatus Bahía Culebra, Guanacaste Abundant 12 2014–2016 Asteropsis carinifera Zenopontonia soror Bahía Culebra, Guanacaste Abundant 12 2014–2016 Astropecten regalis Minyocerus kirki Manglar de Térraba-Sierpe, Puntarenas Rare 8 2013 Nidorellia armata Zenopontonia soror Bahía Salinas, Guanacaste Abundant 3–8 2014–2016 Nidorellia armata Zenopontonia soror Bahía Culebra, Guanacaste Abundant 3 2014–2018 Pentaceraster cumingi Zenopontonia soror Isla Tortuga, Golfo de Nicoya, Puntarenas Abundant 6 2013 Pentaceraster cumingi Zenopontonia soror Golfo Dulce, Puntarenas Abundant 2–16 2014 Pentaceraster cumingi Zenopontonia soror Bahía Cuajiniquil, Golfo de Santa Elena Abundant 25 2014–2016 Pentaceraster cumingi Zenopontonia soror Bahía Culebra, Guanacaste Abundant 2–12 2014–2018 Pharia pyramidata Zenopontonia soror Bahía Culebra, Guanacaste Abundant 4–6 2014–2016 Phataria unifascialis Zenopontonia soror Nicuesa, Golfo Dulce, Puntarenas Abundant 2.5 2014 Phataria unifascialis Zenopontonia soror Bahía Culebra, Guanacaste Abundant 4–6 2014–2016 Echinoidea Astropyga pulvinata Tuleariocaris holthuisi Bahía Culebra, Guanacaste Abundanta 6–8 2013–2014 Centrocidaris Pseudocoutierea elegans Parque Nacional Isla del Coco Abundant 85–103 2009, 2013, Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 5 of 13 tem is in a phase shift, where some macroalgae have increased their abundance and become dominant, e.g., Caulerpa sertularioides (Fernández-García et al. 2012; Arias-Godínez et al. 2019). Several collections were done at the Islas Murciélago, an archipelago in Área de Conservación Guanacaste (Cortés 2017). In the Gulf of Nicoya, specimens were obtained from the coral communities of Isla Tortuga, where coral cover is below 5% and of low diversity (Alvarado et al. 2018), as well as from the intertidal mudflat of Punta Morales, where polychaete worms and ostracods pre- dominate (Vargas 1987). Punta Nicuesa is a coral community with one of the highest covers of live coral along the southern Pacific coast (up to 83.4%) (Alvarado et al. 2015). Isla del Coco is the site with the greatest protection in Pacific Costa Rica; coral cover there is reported to be 18.64 ± 3.55% (Alvarado et al. 2016a; Cortés 2016b). Collection Collection of specimens was carried out in a targeted way. The available environments of most sites were ex- plored from the intertidal zone to ~ 30m deep, including mudflats, sandy beaches and rocky shores, coral and rocky reefs, rhodolith beds and subtidal soft bottoms. Different organisms that are known to be decapod hosts were collected and accommodated in separate plastic bags. Each of the collected specimens underwent a de- tailed visual inspection and the water was filtered to sep- arate possible decapod symbionts. In general, echinoids, asteroids, holothuroids, octocorals and scleractinian corals were collected and externally inspected, while the interiors of the bivalves were inspected. Occasionally, sponges and annelids were collected. Most of the sam- ples were collected manually in the intertidal zone and by scuba diving in the subtidal environments (Table 1). In the case of Isla del Coco, samples from two dives in the submarine DeepSee (Cortés and Blum 2008; Cortés 2019) that explored rocks in deep locations (between 60 and 280 m) were inspected. The sampling was opportun- istic, which means that search efforts were not the same to all sites. Our results include a species list of collected deca- pods associated with other organisms along the Pa- cific of Costa Rica, and their relative abundance. In addition, information is included from specimens collected in the Costa Rican Pacific, both on the coast and in Isla del Coco, which were in the collec- tion of the Zoology Museum, University of Costa Rica (MZUCR, for its abbreviation in Spanish). These collections were carried out between 1970 and 2019; they included the intertidal zone, scuba diving to 40 m, dives of the submarine DeepSee to depths between 60 and 280 m and a dive of the submarine ALVIN to 1000 m deep (Tables 1 and 2). The list that is presented also includes the decapod associa- tions that have previously been reported in the lit- erature for Pacific Costa Rica. Species identification were done using Rathbun (1918, 1930, 1931), Holthuis (1951), Haig (1960), Williams (1986), Kim and Abele (1988), Kropp (1989), Ramos (1995), Cas- tro (1996), Hendrickx (1999), Vargas (2000), Thoma et al. (2005), Marín and Anker (2009), Campos and Hernández-Ávila (2010). All names are according to WoRMS (http://www.marinespecies.org, last accessed 14 December 2020). Results One-hundred associations are reported, which include 74 species of decapods are guests of six phyla of hosts (Table 1). The phylum with the most associated deca- pods was Cnidaria, with 74 species i.e., 74% of the total), followed by Echinodermata with 15 species, and four each with Annelida and Mollusca, two with Chordata, Table 1 Hosts, associated decapods, sites, depth and year of collections (Continued) Host Phylum Host Group Host Species Associated species Site Abundance Depth (m) Year doederleini 2016 Diadema mexicanum Stenorhynchus debilis Isla Tortuga, Golfo de Nicoya, Puntarenas Abundant 2–15 2014–2019 Diadema mexicanum Tuleariocaris holthuisi Bahía Culebra, Guanacaste Abundanta 2–8 2014 Encope micropora Dissodactylus nitidus Bahía Salinas, Guanacaste Rare NI 2005 Lanthonia longifissa Dissodactylus nitidus Playa Costa de Oro, Coyote, Guanacaste Rare NI 2010 Tripneustes depressus Gnathophylloides mineri Bahía Wafer, Parque Nacional Isla del Coco Rare 15 2016 Chordata Ascidiacea Rhopalaea birkelandi Ascidonia pusilla Playas del Coco, Bahía Culebra, Guanacaste Rare Shallow 1970 NI Ascidonia pusilla Isla Bolaños, Bahía Salinas, Guanacaste Rare NI 2012 NI No information aSeasonally abundant, otherwise rare Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 6 of 13 http://www.marinespecies.org Table 2 Decapods associated with other invertebrates on Pacific Costa Rica # Species Infraorder Family MZUCR 1 Trizopagurus magnificus (Bouvier, 1898) Anomura Diogenidae NC 2 Munida sp. Leach, 1820 Munididae 3521 3 Iridopagurus occidentalis (Faxon, 1893) Paguridae 2483 4 Pagurus lepidus (Bouvier, 1898) Paguridae NC 5 Euceramus transversilineatus (Lockington, 1878) Porcellanidae 3266 6 Megalobrachium tuberculipes (Lockington, 1878) Porcellanidae 3312, 3408 7 Minyocerus kirki Glassell, 1938 Porcellanidae 3327 8 Orthochela pumila Glassell, 1936 Porcellanidae 3312 9 Pachycheles velerae Haig, 1960 Porcellanidae 2746 10 Pachycheles biocellatus (Lockington, 1878) Porcellanidae 3709–03 11 Petrolisthes artifronsa Haig, 1960 Porcellanidae 2552 12 Petrolisthes haigae Chace, 1962 Porcellanidae NC 13 Polyonyx nitidus Lockington, 1878 Porcellanidae 3413 14 Coralaxius galapagensis Kensley, 1994 Axiidea Axiidae 2733, 2738 15 Paracallianidea laevicaudaa (Gill, 1859) Callianideidae 2552 16 Hapalocarcinus marsupialis Stimpson, 1859 Brachyura Criptochiridae 1652, 1924 17 Opecarcinus crescentus (Edmondson, 1925) Criptochiridae 1646, 1801, 1957 18 Domecia hispida Eydoux & Souleyet, 1842 Domeciidae 1929 19 Pachygrapsus transversus (Gibbes, 1850) Grapsidae 2552 10 Stenorhynchus debilis (Smith, 1871) Inachoididae 3461 21 Ala cornuta (Stimpson, 1860) Mithracidae NC 22 Amphithrax tuberculatus (Stimpson, 1860) Mithracidae 2364 23 Hemus finneganae Garth, 1958 Mithracidae 2607 24 Nemausa sinensisa (Rathbun, 1892) Mithracidae 2413 25 Teleophrys cristulipes Stimpson, 1860 Mithracidae NC 26 Uca (Petruca) panamensis (Stimpson, 1859) Ocypodidae 2552 27 Eupilumnus xantusiia (Stimpson, 1860) Oziidae 2744 28 Panopeus chilensis H. Milne Edwards & Lucas, 1843 Panopeidae 3272 29 Pilumnus stimpsoniia Miers, 1886 Pilumnidae 3466 30 Austinotheres angelicus (Lockington, 1877) Pinnotheridae 1627, 2831, 2832, 2833, 3068, 3069 31 Calyptraeotheres pepeluisib E. Campos and Hernández-Ávila, 2010 Pinnotheridae 3279 32 Calyptraeotheres sp.b E. Campos, 1990 Pinnotheridae 3709–01 33 Dissodactylus nitidus Smith, 1870 Pinnotheridae 2859, 3052 34 Glassella costaricana (Wicksten, 1982) Pinnotheridae 1883, 2564, 2605, 2606, 2685, 2911, 3107, 3115, 3194, 3271, 3311, 3452, 3453, 3506, 3530 35 Parapinnixa cortesi B. P Thoma, Heard & Vargas, 2005 Pinnotheridae 2552 36 Pinnixa longipes (Lockington, 1876) Pinnotheridae 3413 37 Raytheres clavapedatusb (Glassell, 1935) Pinnotheridae 2604 38 Tetrias scabripes Rathbun, 1898 Pinnotheridae 2821 39 Quadrella nitida Smith, 1869 Trapeziidae 1963, 2309, 2730, 2737 40 Trapezia bidentata (Forskål, 1775) Trapeziidae 2294, 2852, 3565 41 Trapezia corallina Gerstaecker, 1856 Trapeziidae 2851 42 Trapezia cymodocea (Herbst, 1801) Trapeziidae 1929 43 Trapezia digitalis Latreille, 1828 Trapeziidae 1010 Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 7 of 13 and one with Porifera. The host order with the greatest diversity of associated decapods was Scleractinia (Table 1). The species that showed the most associations with different hosts was Zenopontonia soror, which was found in five species of seastars (Table 1). This species was re- cently reported new to Costa Rica by Vargas-Castillo and Cortés (2019). The shrimp Pseudocoutierea elegans was found in hosts from three groups (Octocorallia, Hydrozoa, and Echinoidea). On the other hand, Tetrias scabripes was found associated solely with polychaetes (Table 1). Of the associations recorded 59% were rare, that is, we observed them in a few occasions or with few in- dividuals. While 36% of the associations were ob- served many times and with several members of the symbiont species on the host. Four relations were very abundant, three of them, Hemus finneganae, Ste- norhynchus debilis and Pachygrapsus transversus with hard corals, and Austinotheres angelicus with a bi- valve. On the other extreme was Pontonia simplex of which we found only one specimen in a bivalve. Tuleariocaris holthuisi, associated with two species of Table 2 Decapods associated with other invertebrates on Pacific Costa Rica (Continued) # Species Infraorder Family MZUCR 44 Cycloxanthops vittatus (Stimpson, 1860) Xanthidae NC 45 Heteractaea lunata (Lucas in H. Milne Edwards & Lucas, 1844) Xanthidae NC 46 Lipaesthesius leeanus Rathbun, 1898 Xanthidae 2607 47 Lipkemedaeus spinulifera (Rathbun, 1898) Xanthidae 3461 48 Platypodiella rotundata (Stimpson, 1860) Xanthidae 2813 49 Williamstimpsonia stimpsoni (A. Milne-Edwards, 1879) Xanthidae 2853–05 50 Alpheus floridanusa Kingsley, 1878 Caridea Alpheidae 2552 51 Alpheus lottini Guérin-Méneville, 1838 [in Guérin-Méneville, 1829–1838] Alpheidae 2364, 3565 52 Synalpheus sp. Spence Bate, 1888 Alpheidae 3466 53 Hippolyte sp. Leach, 1814 [in Leach, 1813–1815] Hippolytidae 3187 54 Ascidonia pusilla Holthuis, 1951 Palaemonidae 3302 55 Brachycarpus biunguiculatus (H. Lucas, 1846) Palaemonidae 3565 56 Fennera chacei Holthuis, 1951 Palaemonidae 2851, 2852 57 Harpiliopsis depressa (Stimpson, 1860) Palaemonidae 1929 58 Gnathophylloides mineri Schmitt, 1933 Palaemonidae NC 59 Gnathophyllum panamensea Faxon, 1893 Palaemonidae 2744 60 Neopontonides henryvonprahli Ramos, 1995 Palaemonidae 2234, 3312, 3408, 3434 61 Periclimenes infraspinis (Rathbun, 1902) Palaemonidae 3187 62 Periclimenes murcielagensis Vargas, 2000 Palaemonidae 2247, 2308, 2309, 3526 63 Periclimenes sp. O.G. Costa, 1844 Palaemonidae 3187 64 Pontonia margaritaa Smith in Verrill, 1869 Palaemonidae 1572, 1682, 3186, 3188 65 Pontonia simplex Holthuis, 1951 Palaemonidae 2202 66 Pseudocoutierea elegansa Holthuis, 1951 Palaemonidae 2731, 3521, 3350 67 Pseudoveleronia laevifronsa (Holthuis, 1951) Palaemonidae 2233, 2413, 3312, 3408, 3434 68 Tuleariocaris holthuisib Hipeau-Jacquotte, 1965 Palaemonidae 3443, 3444, 3446 69 Typton sp. O.G. Costa, 1844 Palaemonidae 3434 70 Veleronia serratifrons Holthuis, 1951 Palaemonidae 2233 71 Veleronia sympathesa (De Ridder & Holthuis, 1979) Palaemonidae 2727 72 Waldola schmitti Holthuis, 1951 Palaemonidae 2247, 2309 73 Zenopontonia soror (Nobili, 1904) Palaemonidae 3445, 3449, 3709–02 74 Pomatogebia rugosaa (Lockington, 1878) Gebiidea Upogebiidae 1770, 1925 MZUCR Catalogue number of the Zoology Museum, University of Costa Rica, NC Not catalogued aNew reports for Isla del Coco = 14 bNew reports for Costa Rica = 4 Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 8 of 13 sea urchins, was seasonally abundant but rare at other times. A species that was abundant was always abun- dant, with very few exceptions, Megalobrachium tuberculipes and Pseudoveleronia laevifrons were abundant in one species of octocoral, Eugorgia mut- abilis, but not in other octocorals. Symbiotic species were usually associated to the same species or group of related species, being an exception P. elegans that was abundant in an octocoral, a calcareous hydroid and a sea urchin (Table 1). In total, 74 species of symbiotic decapods have been discovered in Pacific Costa Rica, 13 anomurans, two axiidids, 34 brachyurans, 24 carideans, and one gebii- did (Table 2). The family with the most symbiotic species was Palaemonidae (20 spp.), followed by the families Pinnotheridae and Porcellanidae, with nine species each. The genus with the most species was Trapezia with four, followed by Periclimenes with three. Fourteen new reports of decapods were re- corded for Isla del Coco along with the occurrence of four new decapod records for Pacific Costa Rica, Calyptraeotheres pepeluisi Campos and Hernández- Ávila 2010, Raytheres clavapedatus (Glassell, 1935), Tuleariocaris holthuisi Hipeau-Jacquotte 1965 and Pseudocoutierea elegans Holthuis 1951. This is the first time that the genus Calyptraeotheres is reported in Costa Rica (Table 2). In the following section, the associations are detailed according to the type of host (Table 1). Porifera In this study, only the species Panopeus chilensis is re- ported to be associated with an intertidal sponge, genus Halichondria. However, this is probably because the few studies on sponges have not focus on documenting the associated organisms. Cnidaria Fifty-six species of decapods, distributed in five orders, 23 families and 50 genera, were found associated with 21 spe- cies of cnidarians. Opecarcinus crescentus has only been found in Pavona gigantea, while Alvarado and Vargas- Castillo (2012) reported 16 species of decapods associated with Pocillopora damicornis, all of which are typically found with this host. Six additional species are reported associated to Pocillopora sp. Seven species were found liv- ing on Porites lobata and one, Platypodiella rotundata, exclusively on Tubastraea coccinea. Fifteen species were found associated with Antipatharia. The two species asso- ciated with Antipathes sp. were also found in Myriopathes panamensis. Only one associated deep-water decapod, Coralaxius galapagensis, was found on Lillipathes rita- mariae. In Octocorallia, 22 associated species were found. Eugorgia mutabilis was the host with the greatest diversity of decapods, six. The two most common decapods in octocorals were Neopontonides henryvonprahli and Pseu- doveleronia laevifrons; four crustaceans could not be iden- tified to species. In the hydrozoans, symbionts have only been collected from Stylaster marenzelleri, where Munida sp. and Pseudocoutierea elegans were found. Mollusca Four species of decapods, distributed in two orders, two families and three genera, were found associated with four species of molluks. Symbionts have been found pri- marily in bivalves. In specimens of the pearl oyster Pinc- tada mazatlanica, pairs of the shrimp Pontonia margarita have been found living inside the oyster on numerous occasions; P. simplex was found in Pinna ru- gose. In the oyster, Saccostrea palmula, the pinnotherid crab Austinotheres angelicus has been reported as a guest with a prevalence of 38% (Mena et al. 2014). Only pairs of Calyptraeotheres pepeluisi were found living in the interior of the gastropod Crepidula sp. on the man- grove roots at Punta Morales. Annelida Four species of decapods, distributed two orders, two families and four genera, were found associated with three species of polychaetes. The tubes of one species of Onuphidae, one species of Terebellidae and the tube of an unidentified family were inspected in the intertidal zone of Punta Morales, Gulf of Nicoya. The Pinnotheri- dae crab, Glassella costaricana was found associated with the polychaete Lanicola sp. The species Pinnixa longipes and Polyonyx quadriungulatus were found in the tube of the onuphids. Echinodermata Nine species of decapods, distributed in two orders, four families and nine genera, were found associated with 12 species of echinoderms. These species were observed liv- ing as epibionts in four species of echinoids and five species of asteroids (Table 1). On the sea star Asteropsis carinifera, three species were found: Pachycheles biocel- latus, Zenopontonia soror and Calyptraeotheres sp., while in the sea star Pentaceraster cumingi and the sea urchin Diadema mexicanum, several individual symbi- onts of both sexes and in different stages of development were found in a single host individual. Symbiotic decapods were found both in solitary and in aggregated echinoderms, such as Astropyga pulvinata and D. mexi- canum in reef sites in Bahía Culebra, the sea star Nidor- ellia armata in rocky reefs close to Playa Rajada, Bahía Salinas, the sea star Pentaceraster cumingi on soft bot- toms near reefs in Golfo Dulce. Aggregates of P. cumingi are common in the rhodolith beds of Isla del Coco, how- ever, no decapods were found associated. Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 9 of 13 The shrimp Z. soror was found in the five sea star spe- cies collected, which belong to the families Oreasteridae (N. armata and P. cumingi), Ophidiasteridae (Pharia pyramidata and Phataria unifascialis) and Asteropsidae (A. carinifera). The shrimp Tuleariocaris holthuisi was found associated with two species of sea urchins of the family Diadematidae (A. pulvinata and D. mexicanum) in Bahía Culebra. Finally, a female of Gnathophylloides mineri was found associated with Tripneustes depressus in Bahía Wafer, Isla del Coco, at a depth of 8 m. Chordata Only one species of decapod, A. pusilla, was found asso- ciated with two species of ascideans. In 1970, Ascidonia pusilla was collected from specimens of the recently de- scribed ascidian Rhopalaea birkelandi from Playas del Coco, Bahía Culebra (Fujino 1972), and was described as Pontonia spighti. A specimen of A. pusilla was found in association with an unidentified sea squirt (Ascidiacea) from Isla Bolaños, northern Pacific Costa Rica. Symbiotic decapods in Isla del Coco In total, 28 associations of 24 species of decapods, in five ordens and 17 families, were found at Isla del Coco. Of the species found, 10 belong to the infraorder Brachyura and 10 to the infraorder Caridea, associated with nine orders distributed among four phyla (Tables 1 and 2). Discussion In Costa Rica, few studies have focused on symbiotic decapods, with the majority carried out in the Pacific and only one in the Caribbean (Azofeifa-Solano et al. 2014). Most of these studies were focused on reproduct- ive aspects of decapod guests. Fifty percent of the studies deal with pea crabs (Pinnotheridae), 35% are about the shrimp family Palaemoniidae, and the remaining 15% are derived from studies of the diversity of organisms as- sociated with the coral P. damicornis (Cabrera-Peña and Solano-López 1996; Cabrera-Peña et al. 2001; Alvarado and Vargas-Castillo 2012; Azofeifa-Solano et al. 2014; Mena et al. 2014; Salas-Moya et al. 2014). There is a need for more detailed studies of decapod crustaceans associated with macroinvertebrates. In this study, T. holthuisi is reported from Bahía Culebra, where 24 individuals (juvenile, adult, egg bear- ing females, females without eggs and males) were asso- ciated with D. mexicanum and A. pulvinata collected in 2013 and 2014. This species is distributed from the east coast of Africa (Hipeau-Jacquotte 1965; Bruce 1982), the north east of Australia (Bruce 1990) and in Tahiti (J. Poupin pers. comm. in Marín and Anker 2009). It has also been found in Baja California, Mexico, where two individuals were collected (Wicksten and Hernández 2000) and in Isla Coiba, Panama, where an egg-bearing female was captured (Marín and Anker 2009). Bruce (1982) reported that T. holthuisi was found in different species of sea urchins in the Indo-Pacific, for example Astropyga radiata, Echinothrix diadema, Stomopneustes variolaris and Echinometra mathaei. However, in the eastern tropical Pacific, T. holthuisi has only been found associated with the black sea urchin, D. mexicanum (Wicksten and Hernández 2000; Marín and Anker 2009). We have continued surveying and collecting the sea urchins D. mexicanum and A. pulvinata, but T. holthuisi has not been observed again. These results may be due to the fact that the sea urchins in Bahía Culebra displayed the highest population density levels of the eastern tropical Pacific after serious degradation of the reefs and a series of harmful algal proliferations of phytoplankton between 2005 and 2006 (Alvarado et al. 2012, 2016b). But in recent years the populations of sea urchins have declined, possibly due to the continual deg- radation of the reefs (Alvarado et al. 2018), which might explain the absence of T. holthuisi. Knowledge on Psedocoutierea elegans in the region is scarce. It has been reported for the Gulf of California and in the Galapagos Islands (Holthuis 1951). Because the collection method in this case was with the submar- ine DeepSee, which uses an arm and single specimen container that does not permit the separation of collec- tion events, the authors consider that it is possibly asso- ciated with the sea urchin Centrocidaris doederleini, since it has been found associated with this species on three occasions (2009, 2013, 2016). New collection sur- veys of C. doederleini are recommended to confirm this association at Isla del Coco. It could be assumed that P. elegans tends to be more of a generalist in its host selec- tion due to the low availability of hosts in the deep loca- tions where it has been found (greater than 60 m). The shrimp Gnathophylloides mineri is the decapod that is most frequently found associated with the sea ur- chin T. depressus, but we found only one female. It has been reported to represent up to 94% of the decapods associated with Tripneustes ventricosus in Isla Borracha, Venezuela (Vera-Caripe et al. 2017). In Australia, the as- sociation of G. mineri with sea urchins of the genus Tripneustes has also been reported (Bruce 1988). The anomuran (false crab or porcelain crab) Pachy- cheles biocellatus was found to be associated with the seastar A. carinifera. However, it is known that this crab associates primarily with corals (García-Madrigal 1999), and there are reports of the species in rocky reefs or in sites near small coral colonies (García-Madrigal 2009). Another species that was found associated with A. cari- nifera is the pea crab from the family Pinnotheridae, Calyptraeotheres sp. This genus has already been re- ported by Campos (1990) to be associated with seastars, but it is more common to find it associated with Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 10 of 13 mollusks of the genus Crepidula (Campos and Hernán- dez-Ávila 2010). The cnidarians were the group where the most sym- biont organisms were found. This result was influenced by the study done by Alvarado and Vargas-Castillo (2012), which focused on symbionts of the coral P. damicornis. Additionally, in the case of soft corals, col- lection of associated organisms has been carried out for many years, although not systematically. Possibly, a greater diversity of associated decapod species may be found by increasing research efforts in a systematic way. Of the 21 species found, 14 are new reports for Isla del Coco, according to the compilation done by Cortés (2012). The host in which the greatest number of symbiotic species at Isla del Coco was the black coral, Myriopathes panamensis. Host information was re- corded for some of the decapod specimens of Isla del Coco in the collection of the MZUCR but not for others, as they were not collected in targeted surveys. A small fraction of Pacific Costa Rica was surveyed. Even so, 14 new records of decapods associated with macroinvertebrates were found in the very well-studied Isla del Coco and four new records were discovered for Costa Rica. These results highlight the need to conduct more detailed studies in which time of year, depth, physico-chemical characteristics of the water, type of en- vironment, the abundance of symbionts and hosts, and location in the hosts. This information will help to de- termine the real diversity and ecological importance of the associations between marine organisms. Acknowledgements The authors are grateful for the logistical support of the Centro de Investigación en Ciencias del Mar y Limnología (Research Center in Marine Science and Limnology, CIMAR) and Museo de Zoología (Zoology Museum, MZUCR) of the Universidad de Costa Rica (University of Costa Rica). The authors also thank Conservation International for financing some of the trips, as well as Undersea Hunter Group and its crew for trips to Isla del Coco and for the use of the submarine DeepSee. The authors wish to acknowledge Jaime Nivia, Odalisca Breedy, Cindy Fernández, Sebastián Mena, Kimberly García, Andrés Beita, Cristobal Salamé, Yolanda Camacho, Fiorella Vázquez and Benjamin Chomitz for their support with collecting samples. Samples were collected under the following resolutions of the Ministry of the Environment of Costa Rica: 015-2013, 065-2013-SINAC, 2016-I-ACMIC-022, ACMIC-I-2016-012, ACMC-I-2017-06, R-SINAC-PNI-SE-002-2018, ACT-OR-DE- 024-18, R-SINAC-ACG-PI-041-2019, R-SINAC-PNI-ACLAP-035-2019, 04-2019-I- ACMC. The detailed review of the manuscript by Marjorie Reaka and of an anonymous reviewer is greatly appreciated. Authors’ contributions All authors contributed to the study conception and design. Material collection, preparation, data collection and analysis were performed by all authors, especially CSM and RVC. The first draft of the manuscript was written by CSM and checked by all authors. JC prepared the English version and final manuscript that was submitted and the revised darft. JCAS prepared the map. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Funding This work was supported with personal funds from CSM and JCAS; a grant from Conservation International to JJA; grants from the Vicerrectoría de Investigación, Universidad de Costa Rica (UCR) [Grants numbers 808–98-013, 808-A5–037] to JC, [Grants numbers 808-B3–503, 808-B6–520] to JJA; salaries from UCR to RVC, JJA, JCN; and donated space in the vessel and submarine by Undersea Hunter. Availability of data and materials Museo de Zoología (Zoology Museum), Universidad de Costa Rica database.) Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Author details 1Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San Pedro, San José 11051-2060, Costa Rica. 2Escuela de Biología, Universidad de Costa Rica, San Pedro, San José 11051-2060, Costa Rica. 3CIBET-Museo de Zoología, Universidad de Costa Rica, San Pedro, San José 11051-2060, Costa Rica. Received: 4 June 2020 Accepted: 22 December 2020 References Alfaro EJ, Cortés J, Alvarado JJ, Jiménez C, León A, Sánchez-Noguera C, Nivia-Ruiz J, Ruiz E. Clima y temperatura sub-superficial del mar en Bahía Culebra, Golfo de Papagayo, Costa Rica. Rev Biol Trop. 2012;60(Suppl 2):159–71. https://doi. org/10.15517/rbt.v60i2.20000. Alvarado JJ, Beita-Jiménez A, Mena S, Fernández-García C, Guzmán-Mora A, Cortés J. Ecosistemas coralinos del Parque Nacional Isla del Coco, Costa Rica: estructura y comparación 1987–2014. Rev Biol Trop. 2016a;64(Suppl 1):S153– 75. https://doi.org/10.15517/rbt.v64i1.23423. Alvarado JJ, Beita-Jiménez A, Mena S, Fernández-García C, Guzmán-Mora AG. Osa conservation area (Costa Rica) coral ecosystems: structure and conservation needs. Rev Biol Trop. 2015;63(Suppl 1):219–59. Alvarado JJ, Beita-Jiménez A, Mena S, Fernández-Gracía C, Cortés J, Sánchez- Noguera C, Jiménez C, Guzmán-Mora AG. Cuando la conservación no puede seguir el ritmo del desarrollo: Estado de salud de los ecosistemas coralinos del Pacífico Norte de Costa Rica. Rev Biol Trop. 2018;66(Suppl 1):S280–308. https://doi.org/10.15517/rbt.v64i1.23423. Alvarado JJ, Cortés J, Guzmán HM, Reyes-Bonilla H. Density, size and biomass of Diadema mexicanum (Echinoidea) in Eastern Tropical Pacific coral reefs. Aquat Biol. 2016b;24:151–61. https://doi.org/10.3354/ab00645. Alvarado JJ, Cortés J, Reyes-Bonilla H. Reconstruction of Diadema mexicanum bioerosion impact on three Costa Rican Pacific coral reefs. Rev Biol Trop. 2012;60(Suppl 2):121–32. https://doi.org/10.15517/rbt.v60i2.19975. Alvarado JJ, Vargas-Castillo R. Invertebrados asociados al coral constructor de arrecifes Pocillopora damicornis en Playa Blanca, Bahía Culebra, Costa Rica. Rev Biol Trop. 2012;60(Suppl 2):77–92. https://doi.org/10.15517/rbt. v60i2.19965. Anthony KRN, Cannolly SR. Environmental limits to growth: physiological niche boundaries of corals along turbidity-light gradients. Oecologica. 2004;141: 373–84. https://doi.org/10.1007/s00442-004-1647-7. Arias-Godínez G, Jiménez C, Gamboa C, Cortés J, Espinoza M, Alvarado JJ. Spatial and temporal changes in reef fish assemblages on disturbed coral reefs, north Pacific coast of Costa Rica. Mar Ecol. 2019:e12532. https://doi.org/10. 1111/maec.12532. Azofeifa-Solano JC, Elizondo-Coto M, Wehrtmann IS. Reproductive biology of the sea anemone shrimp Periclimenes rathbunae (Caridea, Palaemonidae, Pontoniinae), from the Caribbean coast of Costa Rica. ZooKeys. 2014;457: 211–25. https://doi.org/10.3897/zookeys.457.7380. Baeza JA. The origins of symbiosis as a lifestyle in marine crabs (genus Petrolisthes) from the eastern Pacific: does interspecific competition play a role? Rev Biol Mar Oceanogr. 2007;42:7–21. https://doi.org/10.4067/S0718- 19572007000100002. Baeza JA. Crustaceans as symbionts: an overview of their diversity, host use and life styles. In: Watling L, Thiel M, editors. The life styles and feeding biology of the Crustacea. Oxford: Oxford University Press; 2015. p. 163–89. Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 11 of 13 https://doi.org/10.15517/rbt.v60i2.20000 https://doi.org/10.15517/rbt.v60i2.20000 https://doi.org/10.15517/rbt.v64i1.23423 https://doi.org/10.15517/rbt.v64i1.23423 https://doi.org/10.3354/ab00645 https://doi.org/10.15517/rbt.v60i2.19975 https://doi.org/10.15517/rbt.v60i2.19965 https://doi.org/10.15517/rbt.v60i2.19965 https://doi.org/10.1007/s00442-004-1647-7 https://doi.org/10.1111/maec.12532 https://doi.org/10.1111/maec.12532 https://doi.org/10.3897/zookeys.457.7380 https://doi.org/10.4067/S0718-19572007000100002 https://doi.org/10.4067/S0718-19572007000100002 Baeza JA, Stotz W, Thiel M. Agonistic behavior and development of territoriality during ontogeny of the sea anemone dwelling crab Allopetrolisthes spinifrons (A. Milne-Edwards, 1837) (Decapoda: Anomura: Porcellanidae). Mar Freshw Behav Physiol. 2002;35:189–202. https://doi.org/10.1080/ 1023624021000003817. Bruce AJ. Coral reef Caridea and “commensalism”. Micronesica. 1976;12:83–98. Bruce AJ. The shrimps associated with Indo-west Pacific echinoderms, with the description of a new species in the genus Periclimenes Costa, 1844 (Crustacea: Pontoniinae). Mem Austral Mus. 1982;16:191–216. Bruce AJ. A note on Gnathophylloides mineri Schmitt (Crustacea: Decapoda: Palaemonidae), including its first occurrence in Australian waters. Beagle Rec Nort Terr Mus Arts Sci. 1988;5:97–100. Bruce AJ. A new cnidarian associated palaemonid shrimp from Port Essington, Cobourg Peninsula, Australia. Indo-Malay Zool. 1990;6:229–43. Cabrera-Peña JH, Protti-Quesada M, Urriola-Hernández M, Saénz-Vargas O, Alfaro- Hidalgo R. Tallas y fecundidad de Juxtafabia muliniarum (Brachyura: Pinnotheridae) asociado con Saccostrea palmula (Mollusca: Bivalvia), Costa Rica. Rev Biol Trop. 2001;49:889–94. Cabrera-Peña JH, Solano-López Y. Tamaños y frecuencia de Pontonia margarita (Crustacea: Palaemonidae) asociada a Pinctada mazatlanica (Bivaivia: Pteriidae), Costa Rica. Rev Biol Trop. 1996;44:915–7. Campos E. Calyptraeotheres, a new genus of Pinnotheridae for the limpet crab Fabia granti Glassell, 1933 (Crustacea, Brachyura). Proc Biol Soc Washington. 1990;103:364–71. Campos E, Hernández-Ávila I. Phylogeny of Calyptraeotheres Campos, 1990 (Crustacea, Decapoda, Brachyura, Pinnotheridae) with the description of C. pepeluisi new species from the tropical Mexican Pacific. Zootaxa. 2010;2691: 41–52. https://doi.org/10.11646/zootaxa.2691.1.2. Castro P. Eastern Pacific species of Trapezia (Crustacea, Brachyura: Trapeziidae), sibling species symbiotic with reef corals. Bull Mar Sci. 1996;58:531–54. Cortés J. Marine biodiversity of an Eastern Tropical Pacific oceanic island, Isla del Coco, Costa Rica. Rev Biol Trop. 2012;60(Suppl 3):131–85. Cortés J. The Pacific coastal and marine ecosystems. In: Kappelle M, editor. Costa Rican ecosystems. Chicago and London: University of Chicago Press; 2016a. p. 97–138. Cortés J. Isla del coco: coastal and marine ecosystems. In: Kappelle M, editor. Costa Rican ecosystems. Chicago and London: University of Chicago Press; 2016b. p. 162–91. Cortés J. Marine biodiversity baseline for Área de Conservación Guanacaste, Costa Rica: Published records. ZooKeys. 2017;652:129–79. Cortés J. Isla del Coco, Costa Rica, Eastern Tropical Pacific. In: Loya Y, Puglise KA, Bridge TCL, editors. Mesophotic coral ecosystems. Switzerland: Springer Nature; 2019. p. 465–74. https://doi.org/10.1007/978-3-319-92735-0_26. Cortés J, Blum S. Life to 450 m depth at Isla del Coco, Costa Rica. Rev Biol Trop. 2008;56(Suppl 2):189–206. Cortés J, Jiménez CE, Fonseca AC, Alvarado JJ. Status and conservation of coral reefs in Costa Rica. Rev Biol Trop. 2010;58(Suppl 1):33–50. https://doi.org/10. 15517/rbt.v58i1.20022. De Bary A. Die Erscheinung der Symbiose. Strassburg: Verlag von Karl J. Trubner; 1879. Fernández-García C, Cortés J, Alvarado JJ, Nivia-Ruíz J. Physical factors contributing to the benthic dominance of the alga Caulerpa sertularioides (Caulerpaceae, Chlorophyta) in the upwelling Bahía Culebra, north of Costa Rica. Rev Biol Trop. 2012;60(Suppl 2):93–107. https://doi.org/10.15517/rbt. v60i2.19970. Fujino T. A new Pontoniinid shrimp, Pontonia spighti sp. nov., associated with a newly described ascidian from the Pacific coast of Costa Rica (Decapoda, Natantia, Pontoniinae). Publ Seto Mar Biol Lab. 1972;XIX:293–301. García-Madrigal MS. Anomuros (Anomura) del arrecife de Cabo Pulmo-Los Frailes y alrededores, Golfo de California. Rev Biol Trop. 1999;47:923–8. García-Madrigal MS. Los cangrejos porcelánidos (Decapoda: Anomura) del Pacífico sur de México, incluyendo una lista y clave de identificación para todas las especies del Pacífico oriental tropical. Cien Mar. 2009;13: 23–54. Glynn PW. Fine-scale interspecific interactions of coral reef: functional roles of small and cryptic metazoans. Smithsonian Contr Mar Sci. 2013;39:229–48. Haig J. The Porcellanidae (Crustacea: Anomura) of the eastern Pacific. Allan Hancock Pac Exped. 1960;24:1–440. Hendrickx ME. Los cangrejos braquiuros del Pacifico mexicano (Crustacea: Brachyura: Majoidea y Parthenopoidea). México: CONABIO e Inst. Cienc. Mar Limnol., UNAM; 1999. p. 274. Hipeau-Jacquotte R. Notes de faunistique et de biologie marines de Madagascar. III: Un nouveau Décapode nageur (Pontoniinae) associé aux oursins dans la region de Tulear: Tuleariocaris holthuisi nov. gen. et nov. sp. Rec Trav Stat Mar d’Endoume. 1965;53:247–59. Holthuis LB. A general revision of the Palaemonidae (Crustacea: Decapoda: Natantia) of the Americas. I. The subfamilies Euryrhynchinae and Pontoniinae. Allan Hancock Found Publ Occas Pap. 1951;11:1–332. Kim W, Abele LG. The snapping shrimp genus Alpheus from the Eastern Pacific (Decapoda: Caridea: Alpheidae). Smithsonian Contr Zool. 1988;454:1–119. Kropp RK. A revision of the Pacific species of gall crabs, genus Opecarcinus (Crustacea; Cryptochiridae). Bull Mar Sci. 1989;45:98–129. Macedo PPB, Masunari S, Corbetta R. Crustáceos decápodos associados às cordas de cultivo do mexilhão Perna perna (Linnaeus, 1758) (Mollusca, Bivalvia, Mytilidae) na Enseada da Armação do Itapocoroy, Penha - SC. Biota Neotrop. 2012;12:185–95. https://doi.org/10.1590/S1676-060320120. Marín I, Anker A. On the presence of the pontoniine shrimp, Tuleariocaris holthuisi Hipeau-Jacquotte, 1965 (Decapoda, Pontoniinae) on the Pacific coast of Panamá. Crustaceana. 2009;82:505–8. https://doi.org/10.1163/ 156854008X400577. Martin JW, Davis GE. An updated classification of the recent Crustacea. Los Angeles: Natural History Museum of Los Angeles County; 2001. McCreary JP, Lee HS, Enfield DB. The response of the coastal ocean to strong offshore winds: with application to circulation in the gulfs of Tehuantepec and Papagayo. J Mar Res. 1989;47:81–109. Mena S, Salas-Moya C, Wehrtmann IS. Living with a crab: effect of Austinotheres angelicus (Brachyura, Pinnotheridae) infestation on the condition of Saccostrea palmula (Ostreoida, Ostreidae). Nauplius. 2014;22:151–8. https:// doi.org/10.1590/S0104-64972014000200009. Montfrans J, Ryer CH, Orth RJ. Substrate selection by blue crab Callinectes sapidus megalopae and first juvenile instar. Mar Ecol Prog Ser. 2003;260:209–17. https://doi.org/10.3354/meps260209. Ory N, Dudgeon C, Thiel M. Host-use patterns and factors influencing the choice between anemone and urchin hosts by a caridean shrimp. J Exp Mar Biol Ecol. 2013;449:85–92. https://doi.org/10.1016/j.jembe.2013.09.002. Ramos G. Neopontonides henryvonprahli, una nueva especie de camarón pontonino del Pacifico de Colombia (Decapoda: Palaemonidae) simbionte de las gorgonias Muricea robusta y Lophogorgia alba. Rev Biol Trop. 1995;41:231–7. Rathbun MJ. The grapsoid crabs of America. Bull US Nat Mus. 1918;97:1–461. Rathbun MJ. The cancroid crabs of America of the families Euryalidae, Portunidae, Atelecyclidae, Cancridae and Xanthidae. Bull US Nat Mus. 1930;152:1–593. Rathbun MJ. A new species of pinnotherid crab from Costa Rica. J Washington Acad Sci. 1931;21:262–3. Sal Moyano MP, Schiariti P, Giberto DA, Diaz Briz L, Gavio MA, Mianzan HA. The symbiotic relationship between Lychnorhiza lucerna (Scyphozoa, Rhizostomeae) and Libinia spinosa (Decapoda, Epialtidae) in the Río de la Plata (Argentina-Uruguay). Mar Biol. 2012;159:1933–41. https://doi.org/10. 1007/s00227-012-1980-z. Salas-Moya C, Mena S, Wehrtmann IS. Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae) living in Saccostrea palmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica. ZooKeys. 2014;457: 239–52. https://doi.org/10.3897/zookeys.457.785. Sotka EE. Local adaptation in host use among marine invertebrates. Ecol Lett. 2005;8:448–59. https://doi.org/10.1111/j.1461-0248.2004.00719.x. Starr C, Taggart R, Evers C, Starr L. Biología, la unidad y la diversidad de la vida. México: Cengage Learning Editores, S.A. de C.V.; 2009. Thiel M, Baeza JA. Factors affecting the social behaviour of crustaceans living symbiotically with other marine invertebrates: a modelling approach. Symbiosis. 2001;30:163–90. Thoma B, Heard R, Vargas R. A new species of Parapinnixa (Decapoda: Brachyura: Pinnotheridae) from Isla del Coco, Costa Rica. Proc Biol Soc Washington. 2005;118:543–50. Vargas JA. The benthic community of an intertidal mud flat in the Gulf of Nicoya, Costa Rica. Description of the community. Rev Biol Trop. 1987;35: 299–316. Vargas R. Periclimenes murcielagensis, a new species of shrimp (Crustacea: Decapoda: Palaemonidae) living on black coral from the Pacific coast of Costa Rica. Proc Biol Soc Washington. 2000;113:17–23. Vargas R, Wehrtmann IS. Decapod Crustaceans. In: Wehrtmann IS, Cortés J, editors. Marine biodiversity of Costa Rica, Central America. Dordrecht: Springer and Business Media B.V; 2009. p. 209–28. Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 12 of 13 https://doi.org/10.1080/1023624021000003817 https://doi.org/10.1080/1023624021000003817 https://doi.org/10.11646/zootaxa.2691.1.2 https://doi.org/10.1007/978-3-319-92735-0_26 https://doi.org/10.15517/rbt.v58i1.20022 https://doi.org/10.15517/rbt.v58i1.20022 https://doi.org/10.15517/rbt.v60i2.19970 https://doi.org/10.15517/rbt.v60i2.19970 https://doi.org/10.1590/S1676-060320120 https://doi.org/10.1163/156854008X400577 https://doi.org/10.1163/156854008X400577 https://doi.org/10.1590/S0104-64972014000200009 https://doi.org/10.1590/S0104-64972014000200009 https://doi.org/10.3354/meps260209 https://doi.org/10.1016/j.jembe.2013.09.002 https://doi.org/10.1007/s00227-012-1980-z https://doi.org/10.1007/s00227-012-1980-z https://doi.org/10.3897/zookeys.457.785 https://doi.org/10.1111/j.1461-0248.2004.00719.x Vargas-Castillo R, Cortés J. New records of marine decapods and stomatopods in Área de Conservación Guanacaste (ACG): four years of marine biodiversity inventorying. Mar Biodiv Rec. 2019;12:21. https://doi. org/10.1186/s41200-019-0181-6. Vera-Caripe J, Diaz O, Lira C, Bolaños J. Crustáceos decápodos asociados a Tripneustes ventricosus (Lamarck, 1816) (Echinodermata; Echinoidea) de la Isla La Borracha, Parque Nacional Mochima, Venezuela. Publ Esp Bol Inst Oceanogr Venezuela. 2017;56:61–8. Wehrtmann IS, Cortés J, Echeverría-Sáenz S. Marine biodiversity of Costa Rica: perspectives and conclusions. In: Wehrtmann IS, Cortés J, editors. Marine biodiversity of Costa Rica, Central America. Dordrecht: Springer and Business Media B.V.; 2009. p. 521–33. https://doi.org/10.1007/978-1-4020-8278-8_4998. Wicksten MK, Hernández L. Range extensions, taxonomic notes and zoogeography of symbiotic caridean shrimp of the tropical eastern Pacific (Crustacea: Decapoda: Caridea). Bull South Calif Acad Sci. 2000;99: 91–100. Williams A. Mud shrimps, Upogebia, from the eastern Pacific (Thalassinoidea: Upogebiidae). San Diego Soc Nat Hist Mem. 1986;14:1–60. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Salas-Moya et al. Marine Biodiversity Records (2021) 14:6 Page 13 of 13 https://doi.org/10.1186/s41200-019-0181-6 https://doi.org/10.1186/s41200-019-0181-6 https://doi.org/10.1007/978-1-4020-8278-8_4998 Abstract Introduction Materials and methods Study sites Collection Results Porifera Cnidaria Mollusca Annelida Echinodermata Chordata Symbiotic decapods in Isla del Coco Discussion Acknowledgements Authors’ contributions Funding Availability of data and materials Ethics approval and consent to participate Consent for publication Competing interests Author details References Publisher’s Note