Crustaceans (Decapoda & Stomatopoda) from Golfo Dulce (Pacific, Costa Rica) in the collection of the Museum of Zoology, University of Costa Rica

Introduction: The availability of recently updated lists of species from a particular area is an important first step to evaluate changes in species composition and abundance. Golfo Dulce is a fjord-like embayment with relatively pristine shores and relatively deep waters (200m) that have been sampled occasionally for crustaceans. Methods: In this study the all species from Golfo Dulce deposited in the collection of the University of Costa Rica Museum of Zoology were listed and scientific names were updated. The MZUCR catalog number, station, substrate type, and year or collection were included for each species. Results: A total of 106 species were listed. Neogonodactylus zacae was present in four of the 19 stations represented in the collections for Golfo Dulce. Nine species were present in three stations, 19 in two stations and the remaining 77 in one station each. The families with most species were Ocypodidae y Palaemonidae (7) and Porcellanidae (14). Conclusions: Is necessary to improve our knowledge of the decapods and stomatopods fauna from Golfo Dulce through further samplings. Intertidal sites such as Golfito and Rincón bays have been poorly sampled as well as intertidal and subtidal environment from the western and eastern shores. However, the fauna is relatively rich when it is related to the area of Golfo Dulce (750km2) and is indicative of a relatively undisturbed environment. Updated management policies are urgently needed and this list of species is a step towards this goal.


MATERIALS AND METHODS
The crustacean collection of the Museum of Zoology of the University of Costa Rica (MZUCR) is composed with three components. First, the collection of specimens preserved in 70% ethanol in labeled glass jars. Second, a dossier of handwritten catalog cards, with data for each collecting site. Third, a digital file filled with data obtained from the catalog cards. All catalog entries of marine macrocrustacean species belonging to Golfo Dulce were selected from the digital file. The handwritten cards and the specimen collection were reviewed when sampling data was not clear and/or the species identification was necessary to double-check records. A list of species was assembled, arranged in alphabetical order, and a code number assigned to each one. The list includes the presently accepted species name, authority, catalog number, station and year of collection. Other information such as depth (intertidal, subtidal) and substrate description (rocks, coral, sediment, other) was also included, when available. Two Golfo Dulce species are listed in the cards with no other station data. Most of the specimens in the collection were collected by hand and occasionally by SCUBA while those from the R.V. Victor Hensen expedition were captured with otter and beam trawl nets. All species names were verified for their currently accepted name based in the web page World Register of Marine Species (WORMS).
Ethical, conflict of interest and financial statements: The authors have fully complied with all pertinent and legal requirements both during the study and in the production of the manuscript. We state that there are no conflicts of interest of any kind. The financial sources are fully and clearly stated in the acknowledgements section and we fully.

RESULTS
In total, there were 19 stations for which information was available (Fig. 1). Intertidal and SCUBA diving stations were assigned a code number, while those from trawl nets were identified with capital letters. A total of 106 species of macrocrustaceans with 173 entries was available for Golfo Dulce and catalogued in the collection of the Museum of Zoology (Appendix 1). Of this total, 102 are decapods and four are stomatopods. The earliest collection records are from 1969, followed by a time gap, until 1990 and 1993-1995 when 83 (48%) new entries were listed, many as the result of the R.V. Victor Hensen survey. The next intensive sampling effort took place during 2012-2013. Thirty-nine of the collecting sites were coral rocks, while 32 stations were from sediments. Most of the collecting sites were intertidal. The maximum depth sampled was 200m (Appendix 1).
The 102 species of decapods were distributed into 32 families, while the four species of stomatopods were represented by two (Table 1). The most specious family was the Porcellanidae, with 14 species. Other families, represented by five or more species, are: Ocypodidae (7), Palaemonidae (7), Alpheidae (6), Diogenidae (6), Xanthidae (6), Mithracidae (5), and Portunidae (5). Eleven families were represented by only one species (Table 1). There were ten most frequently species collected in the 19 stations (Table 2). Only one species, the stomatopod Neogonodactylus zacae, was collected at four stations. Nine species were found in three stations, 19 in two stations and the remaining 77 in only one station each. Station 12 had the most species (21), followed by stations 7 (17), 10 (16), 9 (15), and 3 (14). The other stations had less than 10 species each. Stations 1, 13, had one species each ( Table 2). The R.V. Victor Hensen stations located near the sill and at the mouth of Golfo Dulce (F, H, and G, I) included 10, 5, 6, and 6 species, respectively. Those stations in deeper waters inside the gulf had 1 (L) and 3 (M) species.

DISCUSSION
Because almost all the specimens of macrocrustaceans from Golfo Dulce were collected during occasional visits, there is yet to be an intensive sampling effort covering most of the diverse habitats around its shores and in deep waters. The specimens came from a wide variety of habitats. The northern shore is characterized by decaying coral reefs and steep walls while the southern shore has mostly sandy beaches and mangrove swamps. The eastern shore has sandy beaches and a more extense shallow sandy platform. The only survey of deep waters was performed by the R.V. Victor Hensen expedition and it was restricted to a few stations.
Although sampling effort in Golfo Dulce has been relatively important, there is still much additional sampling needed to reach a reliable picture of the invertebrate biodiversity of the embayment. Of relevance are future collections in the area of Golfito Bay where only one entry is reported in the UCR Museum catalogue despite the relatively easy access to many of the environments around this shallow bay. Other relatively unexplored regions are intertidal and subtidal areas near Rincon Bay, the tip of the Osa peninsula, and the sandy beaches and shallow bottoms on the eastern shore. The fact that 77 species were found at only one station each supports the idea that each type of substrate appears to host a characteristic assemblage of species and emphasize the need to explore other sites characterized by different types of substrates.
According to Morales-Ramírez (2011), Golfo Dulce contains 21,5% of the marine biodiversity of the Pacific coast of Costa Rica in an area of about 750km 2 . He also reported a total of 1022 species of different animal groups (invertebrates and vertebrates) for Golfo Dulce. This total represents nearly 1,36 species per km 2 , a figure considered by Morales-Ramírez (2011) to be nearly double than that of the larger (1 990km 2 ) and shallower Gulf of Nicoya estuary, where a more intensive sampling effort has been conducted (Vargas,  . In this context updated information on the biodiversity of the estuary may contribute to a better management of its resources and attract interested visitors. In addition, updated lists are a first step to evaluate structural community changes due to local, regional or global stressors such as coastal development, pollution, and climate change. This list of selected groups of macrocrustaceans presented herein is a step towards these goals.