Marine biodiversity of Costa Rica: Crustacea: Infraorder Anomura

The anomuran crabs are among the best known crustacean groups from the Pacific coast. However, this group is poorly known from the Caribbean coast of Costa Rica. In this compilation based on the literature and the collection at the Zoology Museum, Biology School, University of Costa Rica, we report the presence of 114 species of the Infraorder Anomura for Costa Rica, 20 species from the Caribbean, 96 species from the Pacific (two are present on both coasts). Twenty-nine species are new reports for Costa Rica, 15 from the Caribbean coast (74% of the total of species from that coast) and 14 from the Pacific (15% of the total from the Pacific). The range often species is extended to Costa Rica, siete from the Caribbean and three from the Pacific. Six species are reported for the first time from Cocos Island, where there are also four endemic species.     

Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review

The studies on marine copepods of Costa Rica started in the 1990’s and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.     

Marine biodiversity of Costa Rica: the phyla Sipuncula and Echiura

Fourteen species of Sipuncula belonging to 9 genera have been reported from Costa Rican waters, mostly from the Pacific coast. Three of these species are new records for Costa Rica (Phascolion strombus (Montagu 1804), Aspidosiphon (Aspidosiphon) muelleri Diesing 1851, and Aspidosiphon (Aspidosiphon) gracilis schnehageni (W. Fisher 1946)). One species of Echiura, Thalassema steinbecki Fisher 1946, in the order Echiuroinea, has been reported from the Pacific coast of Costa Rica.     

Requiem for an eastern Pacific seagrass bed

Few papers concerning seagrasses of the eastern Pacific have been published. This paper presents the first ecological data on the seagrass, Ruppia maritima, from a non-lagoonal setting in the eastern Pacific. A 5000 m2 patch formed by R. maritima, at Playa Iguanita, Bahía Culebra, Pacific coast of Costa Rica was studied. Plant density and leaf length of R. maritima were determined along two transects on different dates. Above and below ground biomass were calculated along one transect. Plant density ranged from 1590 to 8630 individuals m(-2) along the two transects, with means of 5990 +/- 1636 and 6100 +/- 1876 plants m(-2) for transect 1 and 2, respectively. Longest leaf length per plant varied between 0.5 and 23.0 cm. Leaf biomass (LB) ranged from 10 to 97 gm(-2), and root-rhizome biomass (RB) from 31 to 411 gm(-2), resulting in RB:LB ratios of 3.07 to 15.27. Total biomass at Bahía Culebra was lower than at tropical lagoons on the Pacific coast of Mexico, but higher than in the Gulf of Mexico. The below ground: above ground biomass ratio was much higher at Bahía Culebra than at other sites on the Pacific coast of Mexico and the Gulf of Mexico. Another seagrass present at Bahía Culebra was Halophila baillonii, with low densities on the deepest section of the patch. At least 44 invertebrate species associated with the seagrass bed have also been identified. The patch at Playa Iguanita and other sites within Bahía Culebra, as well as their associated organisms, disappeared after a severe storm in June 1996. No seagrasses have been found in the area or in any other location on the Pacific coast of Costa Rica since then.     

Effects of the 1991-92 El Niño on scleractinian corals of the Costa Rican central Pacific coast

Coral communities on the central Pacific coast of Costa Rica were affected during the 1991-92 El Ni?o warming event. More than 57% of all observed colonies at three localities (Parque Nacional Manuel Antonio, Punta Cambutal, and Parque Marino Ballena) were bleached. Mortality during this El Ni?o was much lower (approximately 9%) than in previous events. Psammocora spp. accounted for approximately 66% of dead corals, while massive (Porites lobota, Pavona spp.) and branching (Pocillopora spp.) for approximately 34%. Our results suggest that the observed bleaching in P. lobata was related to zooxanthellar densities and not to changes in pigment concentrations: only chlorophyll a varied between normally pigmented and bleached colonies at one locality (Ballena). Site differences in zooxanthellar densities or their pigment concentrations, may not be the result of the bleaching event itself, because a percentage of dead corals and zooxanthellar densities of bleached colonies seems to follow a trend with the exposure to tidal regimes and currents at each site. Local oceanographic conditions can be influencing the zooxanthellar densities and their response to the warming, together with intrinsic differences between colonies as well. The impact of this event can be considered serious given the short period of time that elapsed between El Ni?o related mortalities and the slow reefs recovery, the mode of reproduction of reef building species, and the anthropogenic-originated disturbances which affect the coral communities and reefs of the Costa Rican central Pacific coast.     

Sighting of Stenella attenuata, the spotted dolphin, in Culebra Bay, Costa Rica, 1999-2000

Parallel to a zooplankton study (1999-2000) observations were made (from an inflatable boat), on the presence of dolphins along a transect (-8 km long) on the axis of Culebra Bay (24 km2), Gulf of Papagayo, Pacific coast of Costa Rica. Dolphins were found during 20 of the 31 boat surveys conducted. The only species of cetacean found in the bay was Stenella attenuata, the spotted dolphin. These sightings were more frequent during the rainy season, particularly during the month of May of both years. The presence of S. attenuata in Culebra Bay might be associated to the abundances of fish and mollusks (their presumed prey: for example, squids), as evidenced by fishery statistics available for this zone of the Pacific coast of Costa Rica.     

Marine biodiversity of Costa Rica: class Polychaeta (Annelida)

Three hundred and thirty two species of polychaetes belonging to 50 families are reported for Costa Rica based on previously published reports. In a few families, available material was re-examined and appropriate changes in species identifications were made. Only three species, (Glycera oxycephala Ehlers, 1887; Hemipodia pustulata (Friedrich 1956); and Scolepis (Scolepis) squamata (Miller, 1806)) have been reported from the Caribbean coast of Costa Rica, and these three species have also been reported from the Pacific Coast. The families with more than 15 species are the Spionidae (26), Cirratulidae (24), Nereididae (21), Lumbrineridae (19) and Paraonidae (16). Despite extensive sampling on the Pacific coast over the last 25 years, the Costa Rican polychaete fauna, especially that of the Caribbean coast, remains poorly known.     

New records of benthic marine algae and Cyanobacteria for Costa Rica,and a comparison with other Central American countries

We present the results of an intensive sampling program carried out from 2000 to 2007 along both coasts of Costa Rica, Central America. The presence of 44 species of benthic marine algae is reported for the first time for Costa Rica. Most of the new records are Rhodophyta (27 spp.), followed by Chlorophyta (15 spp.), and Heterokontophyta, Phaeophycea (2 spp.). Overall, the currently known marine flora of Costa Rica is comprised of 446 benthic marine algae and 24 Cyanobacteria. This species number is an under estimation, and will increase when species of benthic marine algae from taxonomic groups where only limited information is available (e.g., microfilamentous benthic marine algae, Cyanobacteria) are included. The Caribbean coast harbors considerably more benthic marine algae (318 spp.) than the Pacific coast (190 spp.); such a trend has been observed in all neighboring countries. Compared to other Central American countries, Costa Rica has the highest number of reported benthic marine algae; however, Panama may have a similarly high diversity after unpublished results from a Rhodophyta survey (Wysor, unpublished) are included. Sixty-two species have been found along both the Pacific and Caribbean coasts of Costa Rica; we discuss this result in relation to the emergence of the Central American Isthmus.     

Harmful blooms of cyanobacteria (Oscillatoriaceae) and dinoflagellates (Gymnodiniaceae) in the Golfo de Nicoya, Costa Rica

Recently, the Pacific coast of Costa Rica has experienced an increase in both magnitude and frequency of harmful algae blooms (HAB). The lack of data regarding the dynamics of these events in the area, and the species of microalgae that produce them, are themes of great interest. The blooms have produced negative impacts on fishery resources and on human health in Costa Rica. In May 2002 a HAB left a large number of dead fish along the central Pacific coast. Water samples were collected using a phytoplankton net and fixed for subsequent processing by electron microscopy. In addition, a one liter sample of surface water was taken for later cell count. In the observed HAB, the dominating organisms found were the cyanobacteria Trichodesmiun erythraeum surrounded by high concentrations of Gram-bacteria and the dinoflagellate Cochlodinium cf. polykrikoides. T. erythraeum, is one of the most important N2 fixing cyanobacteria in marine waters that has been associated with HAB events in diverse parts of the world as well as with symptoms that produce contact dermatitis and other discomforts. C. cf. polykrikoides is a dinoflagellete associated with fish kills; although the type of associated toxins are unknown. In a national newspaper 17 cases of intoxication in humans were reported during this same period, which presented respiratory disorders and burning of the eyes. This is the first report in Costa Rica where a cyanobacteria and a dinoflagellate were observed together producing HAB.     

PHYLOGENETIC RELATIONSHIPS OF GELIDIALES SPECIES IN COSTA RICA

Despite a general paucity of studies on marine algae in Costa Rica, within the red algal order Gelidiales, 9 species are reported from the Caribbean, and 6 species from the Pacific. In this study 5 species from the southeast Caribbean coast and 2 species from the northwest Pacific coast of Costa Rica were collected for DNA sequence and morphological analyses. At the time of this writing, morphological observations of four Caribbean taxa have identified them as Gelidium microdonticum , Pterocladiella capillacea , P. melanoidea , and Gelidiella acerosa. In rbc L sequence analyses, Gelidium microdonticum is resolved within a clade of small Gelidium species predominantly found in the south Atlantic. Two collections representing different forms of Pterocladiella melanoidea sensu Dawson were found to have identical rbc L sequences. These samples were resolved in rbc L trees with a taxon from Texas identified as P. bartlettii and not P. melanoidea from Europe. Comparisons with type material are being made to verify these identifications so that the status of P. melanoidea in the Caribbean may be determined. The unidentified Caribbean taxon is resolved as a distinct species within the Pterocladiella clade as well. Gelidiella acerosa from Caribbean Costa Rica is closely allied with other Caribbean G. acerosa samples in rbc L trees. The two pacific taxa are small intertidal turf species and have not yet been identified. Sequence analyses resolve these taxa within a large clade of Indo-Pacific and Caribbean Gelidium species.     

Seagrass monitoring at Perezoso, Cahuita, Costa Rica (CARICOMP site)

The seagrass of Perezoso (Cahuita National Park, Caribbean coast of Costa Rica) was monitored using the CARICOMP protocol. Productivity (2.7 +/- 1.15 g/m2/d; n=74) was intermediate, compared to other Caribbean sites. Total biomass was intermediate to high (750-1500 g/m2) at most CARICOMP sites (Colombia, Cuba, Mexico, Puerto Rico and Venezuela) including Costa Rica (822.8 +/- 391.84 g/m2; n=32). Turnover rates were high (5.5 +/- 1.36%; n=74) compared to what was found in March and August at other sites. Shoot densities average 725 shoots/m2, in the Caribbean region, while in Costa Rica the value was higher (1184 +/- 335.5 shoots/m2). Average leaf length and width in the entire region were 14.4 cm and 10.6 mm, respectively, similar to what we found, but leaf area index average 3.4 m2 m(-2), higher than what was found in Costa Rica (0.92 m2 m(-2)). At Cahuita, seagrass productivity was significantly lower in March 2005 compared with the previous six years, and biomass has decreased with time. Seagrass productivity and biomass are being affected by the maximum temperatures, which increased by almost 10 degrees C from 1999 to 2005, and show a high negative correlation. Turnover rate and temperature were not correlated. Recreational boating, swimming and nutrient loading from deforested lands in the coast, the upstream rivers and local pollution are potential sources of impact to the seagrass beds at Cahuita.     

Reproductive plasticity in <Emphasis Type="Italic">Petrolisthes armatus</Emphasis> (Anomura,Porcellanidae): a comparison between a Pacific and an Atlantic population

The porcellanid crab Petrolisthes armatus, with a known geographic distribution covering a wide range of latitudes, was selected to conduct a comparative study on egg production and reproductive output between two populations from Pacific and Atlantic coasts. Ovigerous females were collected between September and November 2005 in Punta Morales, Pacific coast of Costa Rica (n = 137) and from March 2005 to July 2006 in Araçá region, São Paulo, Brazil (n = 46). The mean size of females was statistically different between both populations with larger females from Brazil than Costa Rica (7.9 ± 1.31 and 6.6 ± 0.95 mm CW, respectively). Likewise, egg production was significantly different in both populations and started in Pacific Costa Rica at a smaller female size than in Brazil. Specimens from Pacific Costa Rica produced roughly three times more eggs than equally sized females from Brazil, while newly extruded embryos were larger in Brazil than in Costa Rica (0.045 and 0.039 mm³, respectively). Egg volume increased during embryogenesis by 112.8 and 164.5% in Costa Rican and Brazilian populations, respectively. The egg water content increased steadily in both populations; however, eggs produced in Brazil contained always more water than those from the same developmental stage in Costa Rica. Average reproductive output (based on dry weight) was substantially lower in Brazil (0.031) than in Costa Rica (0.065). Our results confirm an impressive intraspecific plasticity of reproductive features in an intertidal decapod. The observed phenotypical variability might be related to local environmental conditions as well as to the location of the studied population concerning its geographic range of distribution.     

Size and distribution of Pandarus satyrus (Copepoda: Pandaridae) on the blue shark Prionace glauca (Carcharhiniformes: Carcharhinidae) in Costa Rica.

A total of 80 specimens of Pandarus satyrus, a cosmopolitan ectoparasitic copepod, were taken from fishery catches of blue sharks (Prionace glauca) in the Eastern Pacific coast of Costa Rica. All specimens were found in the dorsal surface of pectoral fins (8-30 per shark). Longer specimens were most abundant.     

Seawater temperature measured at the surface and at two depths (7 and 12 m) in one coral reef at Culebra Bay, Gulf of Papagayo, Costa Rica

Superficial seawater temperature (SST) and at two depths (7 and 12 m) were measured non-continuously during the study of the corals and coral reefs of Culebra Bay (1993-1996). SST showed seasonal variations of approximately 4 degrees C. The highest average temperatures (27.0 +/- 0.1, range 23-29 degrees C) were during the rainy season from May to November and the lowest (22.9 +/- 0.3 degrees C, 15.5-29 degrees C) during the dry season from December to April. Cold fronts with 2-3 degrees C differences in SST frequently pass into the bay and remain there for several hours according to the tidal cycles. Differences of approximately 3 degrees C between SST and the bottom (5-10 m depth) were usually found, particularly at locations where bottom topography and tidal circulation produced tidal bores. The average temperatures recorded by data loggers placed at 7 and 12 m depth on a coral reef at the outer shores of Culebra Bay, were 27.1 +/- 0.02 degrees C (20.5-31.6 degrees C) and 25.8 +/- 0.04 (9.9-31.5 degrees C) respectively. The seasonal pattern of higher and lower temperatures corresponds respectively to the rainy and dry season of the northern Pacific coast of Costa Rica. Water temperature at 12 m was < 14 degrees C for some hours during an upwelling event whilst minimum temperatures at 7 m were > or = 22 degrees C. Negative temperature anomalies coincided with an increase of the NE-E winds intensity and there is a lunar and tidal component which influence diumal variations of temperature. These results suggest that coral reefs built by branching species (e.g. Pocillopora spp.) in Culebra Bay could be limited by both the influence of cold fronts and by seasonal upwellings which affect negatively those coral species, as reported for other locations in the tropical eastern Pacific.     

The bathymetry of Coco's Island, Costa Rica

The bathymetry of Coco's Island (UNESCO Natural and Cultural World Patrimony), located approximately 500 km from the Pacific coast of Costa Rica, is not well known. It has a high marine biodiversity and also represents a meeting site for many species traveling throughout the Pacific Ocean. The insular shelf is irregular in extension and also in bathymetric features. The northeast limit is defined by the 109.8-128.1 m contours (60-70 fathoms) while the 183 m contour (100 fathoms) practically defines the rest of the island, from which the depth gradient is steep. The maximum extension is to the northeast with a longitude of 13 km. In this context the present limits of the marine park (5 km), are insufficient to protect the whole insular shelf. Current regulation should be modified to prevent fishing activities less than 15 km from the Island.     

Preliminary survey of a nemertean crab egg predator,Carcinonemertes, on its host crab,Callinectes arcuatus (Decapoda,Portunidae) from Golfo de Nicoya,Pacific Costa Rica

The possible presence of egg predators in brood masses of portunid crabs from Pacific Central America has not been studied yet. This survey reports the finding of a nemertean crab egg predator on the portunid crab, Callinectes arcuatus, from the Golfo de Nicoya, Pacific Costa Rica. Nemerteans were found in the egg masses of 26 out of the 74 crabs for a prevalence of 35%. The intensity (mean number of worms/ infected crab) was estimated to be 18 with a variance of 1–123 worms/infected crab. No nemerteans were observed either in the 19 Callinectes arcuatus from Golfo Dulce (southern Pacific coast) and the 10 Portunus asper from Herradura-Jaco (central Pacific coast). This nemertean is a member of the genus Carcinonemertes, which has been reported from the Caribbean coast of Panama. However, the encountered Carcinonemertes sp. is the first published finding and report from Costa Rica and Pacific Central America.     

Theletrum lamothei sp. nov. (Digenea), parasite of Echidna nocturna from Cuajiniquil, Guanacaste, and other digenes of marine fishes from Costa Rica.

A new species of Theletrum is described from the intestine of two palenose morays, Echidna nocturna, collected in Cuajiniquil, Guanacaste Province, Costa Rica. The new species differs from the type species, T. fustiforme Linton, 1910 by having a subspherical pars prostatica, a subspherical seminal vesicle extending anteriorly to the anterior border of the acetabulum, by the presence of a poorly developed hermaphroditic sac, and by having a larger body size. We also report eight additional species of digeneans parasitizing marine fishes in several localities along the Atlantic and Pacific coast of Costa Rica: Bianium simonei, Didymozoinae (metacercariae), Ectenurus virgulus, Hypocreadium myohelicatum, Lecithochirium microstomum, Pseudolecithaster sp., Stephanostomum casum, and Tergestia laticollis. In addition, we present an updated list of helminth parasites of marine fish from Costa Rica and discuss the importance of including parasites as an integral part of biodiversity inventories.     

Recruitment limitation in a tropical intertidal barnacle: Tetraclita panamensis (Pilsbry) on the Pacific coast of Costa Rica

On the central Pacific coast of Costa Rica, populations of Tetraclita panamensis (Pilsbry) were studied to determine the relative importance of pre- and postrecruitment processes in determining patterns of distribution and abundance. Populations at 12 sites on two shores were censused photographically from 1983 to 1985 at 1–3-months intervals, yielding data on recruitment, growth, and mortality. During the 2.5-yr study, recruitment replaced < 24% of the number dying at 10 of the 12 sites. Most populations were sparse and declining. Preemption of settlement was unlikely because bare space was always abundant and recruitment occurred mostly on the shells of adults. Individuals reached a maximum size in 1–3 yr, after which there was little growth. Estimated longevity ranged from 3.6 to 14.7 yr among sites. Mortality was unrelated to submergence, density or the abundance of an important predator, the gastropod Acanthina brevidentata (Wood). Patterns of distribution and abundance among the 12 sites and along the central coast of Costa Rica are probably a function of past variation in recruitment. Many apparently suitable habitats are unoccupied.     

Cloacal and nasal bacterial flora of Lepidochelys olivacea (Testudines: Cheloniidae) from the North Pacific Coast of Costa Rica

Cloacal and nasal bacterial flora of Lepidochelys olivacea (Testudines: Cheloniidae) from the North Pacific coast of Costa Rica. The aerobic cloacal and nasal bacterial flora of 45 apparently healthy female olive ridley sea turtles (Lepidochelys olivacea) was studied at Nancite nesting beach, in Santa Rosa National Park (Costa Rican North Pacific) during July and August 2002. Bacterial samples were obtained by inserting sterile swabs directly into the cloaca and the nasal cavities of the turtles. Ninety-nine aerobic bacterial isolates, including 10 Gram-negative and 5 Gram-positive bacteria, were recovered. The most common bacteria cultured were Aeromonas spp. (13/45) and Citrobacter freundi (6/45) from cloacal samples and Bacillus spp. (32/45), Staphylococcus aureus (6/45) and Corynebacterium spp. (5/45) from nasal ducts. The results of the present study showed that the aerobic bacterial flora of nesting female olive ridleys was composed of several potential human and animal microbe pathogens.     

First record of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in Costa Rica

A survey of entomopathogenic nematodes was conducted in the north Pacific (Guanacaste Conservation Area) and southeast Caribbean (Gandoca-Manzanillo Natural Refuge) regions of Costa Rica. Out of a total of 41 soil samples, 5 were positive for entomopathogenic nematodes (20.5%), with 3 (12.3%) containing Steinernema and 2 (8.2%) Heterorhabditis isolates. Morphological and molecular studies were undertaken to characterize these isolates. The Heterorhabditis isolates were identified as Heterorhabditis indica and the three Steinernema isolates were identified as two new undescribed species. H. indica was recovered from a coastal dry forest. Steinernema n. sp. 1 was isolated from a rainforest valley, between volcanoes. Steinernema sp. n. 2 was isolated from sand dunes in the Caribbean Coast (Punta Uva) near the rainforest strip along the coast. Although limited to two geographic regions, this study suggests entomopathogenic nematodes may be diverse and perhaps widely distributed in Costa Rica. A more intensive survey, covering all geographic regions is currently undergoing.