Pacific Costa Rica Research Articles

New species and records of limpets (Mollusca, Gastropoda) from the Pacific Costa Rica Margin.

The ocean remains a reservoir of unknown biodiversity, particularly in the deep sea. Chemosynthesis-based ecosystems, such as hydrothermal vents and hydrocarbon seeps, host unique and diverse life forms that continue to be discovered and described. The present study focuses on patelliform gastropods (limpets) collected from Pacific Costa Rica Margin hydrocarbon seeps during three research cruises from 2017 to 2019. Genetic and morphological analyses revealed the presence of several new lineages within the genera Bathyacmaea Okutani, Tsuchida & Fujikura,1992, Cocculina Dall, 1882, Paralepetopsis McLean, 1990, and the family Lepetodrilidae McLean, 1988: Bathyacmaealevinae sp. nov., Paralepetopsisvariabilis sp. nov., Pseudolepetodriluscostaricensis gen. et sp. nov., and Cocculinamethana sp. nov. These investigations also expanded the known ranges of the species Pyropeltacorymba McLean, 1992 and Lepetodrilusguaymasensis McLean, 1988 to the Costa Rica Margin. This research highlights the uniqueness of gastropod fauna at the Costa Rica Margin and contributes to our understanding of the biodiversity at chemosynthesis-based deep-sea ecosystems in the face of global biodiversity loss and increased commercial interest in deep-sea resources.

A new species of Heterogorgia Verrill, 1868 (Octocorallia, Malacalcyonacea) from a mesophotic fishing shoal in the eastern Pacific

Heterogorgia abdita sp. nov. is a newly identified mesophotic octocoral species collected at Tigre shoal off Santa Elena Peninsula (Pacific Costa Rica). The new species is described based on distinctive morphological characters that classify it within the genus Heterogorgia. It is characterised by its conspicuous small branching colony with prominent calyces and thin branches. While its scleroma aligns with the genus, the presence of club-like spindles is notable, as these have previously been observed only in the sole Atlantic Heterogorgia species. This study enhances our understanding of the intriguing genus Heterogorgia and contributes to the knowledge of octocoral biodiversity within the Área de Conservación Guanacaste north Pacific Costa Rica and the broader marine biodiversity of the eastern tropical Pacific.

Demand study of freight transportation via railway of four commodity groups: A case study on Costa Rica's Pacific Coast Route

Having railway mobility as an option among transportation modes is of prime importance for the freight logistics of a country and the overall performance of its commerce sector. This work presents a case study in Costa Rica, where freight transportation via railway was formerly available during the last century but has not been in full service since 1995. Specifically, this paper assesses the link connecting the capital city of San Jose to the port of Caldera on the Pacific Ocean coast, henceforth referred to as the “Pacific Coast Route”. Although government institutions and industries alike have stressed the importance of its reactivation in recent years, few efforts have been made to specifically study this route with a level of detail that enables them to understand the composition of freight markets.This study presents a novel demand estimation differentiated by four types of commodities developed to calculate the potential amount of goods that could flow through this corridor, measured in monetary terms and as volumes. Trends in the expected share were analyzed to identify variables that may improve the attractiveness of the railway service and the participation of clients along the route from the country's main economic activities which includes the following: agriculture & livestock, manufacturing, minerals, and forestry.The four-step transportation model was chosen for its suitability towards this case study; where available data sets were limited, the information was aggregated into yearly values, and the network was defined with few transportation zones. Activity-based models were not feasible in this case due to the lack of information on complete routes and volume flows. The model evaluated a first scenario given the present design of the route and a second scenario involving improvements in the alignment and the addition of a new segment.Regarding the opportunities of moving goods according to their type, in terms of volume, minerals (48 %) and agricultural (31 %) have the largest shares of participation in this region, followed by manufacturing (20 %) and forestry products (1 %). However, the manufacturing sector stands out in financial terms, accounting for 71 % of the total value of goods mobilized in the study area.It was found that the demand is most sensible for changes in the service fare, while the benefits of shorter travel times and a larger attraction area in scenario 2 were not significant. A service fee of $USD 2.35/ton in average is recommended to reach a 30 % modal shift towards the railway (following the European Commission's goals to reduce CO2 emissions from freight transportation in 2030).Finally, recommendations for public policies are provided to the entities in the country in the sectors of Agriculture, Health, Energy and Environment, Transportation, and Public Services. The suggestions aim to develop the new railway project with a holistic perspective, considering the inclusion of less profitable economic activities of the surrounding communities that require connectivity, compliance with environmental commitments, and design for resilience while aiming for a financially feasible business model.

New records of Provanna (Gastropoda, Provannidae) from the Costa Rica Margin and an identification key for the genus.

Consistent species identification is foundational to biological research and requires coordination among a diversity of researchers and institutions. However, such consistency may be hindered for rare organisms where specimens, identification resources, and taxonomic experts are few. This is often the case for deep-sea taxonomic groups. For example, the deep-sea gastropod genus Provanna Dall, 1918 is common at chemosynthetic sites throughout the world's oceans, yet no formal guide to these species has yet been produced. Recent exploration has recovered new specimens of Provanna from hydrocarbon seeps off the Pacific Costa Rica Margin. The current work assesses the species identity of these specimens using shell morphology, radular morphology, and genetic barcoding (mitochondrial CO1 and nuclear H3). Records of occurrence for P.laevis Warén & Ponder, 1991, P.ios Warén & Bouchet, 1986, and P.pacifica Warén & Bouchet, 1986 are herein presented from the Costa Rica Margin. A critical taxonomic review of the 29 extant species within this genus was conducted and their genetic, morphological, and biogeographical distinction assessed. In this review, genetic and morphological support was found for nearly all current species delineations except for P.glabraOkutani et al., 1992, syn. nov. and P.laevis, syn. nov., which are herein synonymized to P.laevis, and for P.ios, syn. nov. and P.goniata Warén & Bouchet, 1986, syn. nov., which are synonymized to P.ios. Finally, the first species identification key for the extant species in this genus is presented. This work clarifies the taxonomy and systematics of this deep-sea gastropod genus and contributes a novel polytomous key for use in future research.

Response of diatom communities to climate and human disturbance: A 4200-year record from Costa Rica

This study integrates diatom analysis with existing records of pollen, charcoal, elemental composition, and stable light isotopes to expand upon the 4200-year history of human activity and climate change from Laguna Los Mangos in southern Pacific Costa Rica. We counted diatoms in peroxide-treated samples and analyzed community composition using cluster analysis, revealing four distinct assemblage zones with diatom variability most closely correlated with phosphorus, titanium, and organic content. The earliest assemblage (Zone D, 4150–3430 cal yr BP) was dominated by Encyonema silesiacum and Nitzschia incognita and aligned with a period of deforestation, erosion, and abundant macrophytes. Gomphonema affine proliferated in Zone C (3430–2450 cal yr BP), reflecting increased pH and productivity likely caused by agriculture-induced nutrient loading. We attributed the preservation gap from 3290 to 2970 cal yr BP in Zone C to silica depletion and erosional deposition that induced decline in diatom abundance by diluting valve concentrations in lake sediments. Nitzschia incognita and G. affine became the dominant taxa in Zone B (2450–1400 cal yr BP), likely reflecting eutrophy, increasing conductivity, and drying climate. Dominance of Diadesmis confervacea indicated reduced lake level in Zone A (1400 cal yr BP–modern) at the onset of the Terminal Classic Drought (TCD). A hiatus in the record indicates lake desiccation from 950 to 450 cal yr BP. During the Little Ice Age (LIA), diatoms reflect conditions similar to Zone B indicating increased lake level, circumneutral pH, and eutrophy. Refilling of the lake indicates increased precipitation during the LIA despite evidence of severe regional drought reported at other sites. Variable precipitation during this period likely resulted from the combined effects of Spanish contact, agricultural collapse, forest recovery, and shifts in Atlantic and Pacific climate forcing mechanisms. Overall, the Los Mangos diatom record reflects shallow, slightly alkaline, eutrophic conditions influenced by nutrient enrichment, erosion, and deforestation associated with maize agriculture.

Biogeography and depth partitioning in deep‐sea gastropods at the Pacific Costa Rica Margin

AbstractAimUnderstanding the global distribution of biodiversity and the factors that influence it are among the central goals of biogeography. How abiotic and biotic factors limit species' ranges has been investigated across a variety of environments and taxonomic groups. However, such investigations across oceanic depths remain underrepresented, particularly for chemosynthetic environments such as hydrocarbon seeps. The depth differentiation (DD) hypothesis suggests that steep environmental gradients in the upper depths of the ocean may limit species' ranges over relatively short vertical distances. The present study aims to investigate the evidence for the DD hypothesis at hydrocarbon seep sites along the Pacific Costa Rica Margin (CRM) by investigating the biogeographic distributions of gastropods sampled there and the factors that influence them.LocationCosta Rica.TaxonMollusca, Gastropoda, Provannidae, Genus: Provanna (Dall, 1918).Methods1813 Provanna snails were collected across 1300 metres (m) of depth from Costa Rican hydrocarbon seeps. To test the DD hypothesis, species partitioning across the depth range was investigated. In addition to gradients in oceanographic conditions, such as temperature, oxygen, and salinity, other factors potentially responsible for filtering species were also considered as alternative hypotheses, including the availability of biogenic substrate, the availability of and reliance on chemosynthetic fluids, and specific preferences for certain environmental conditions.Results and Main ConclusionsThree species of Provanna were identified from the CRM and exhibited partitioning across depth. For the two dominant species (P. laevis and P. goniata), the data suggest that depth‐associated oceanographic conditions are more likely than any other factor investigated to explain their observed partitioning across depth, supporting the DD hypothesis. This study also presents novel evidence that such partitioning may be unilaterally determined, wherein species with narrower depth ranges may limit the local depth ranges of others. This study represents an extension of biogeographic range limit literature into chemosynthetic habitats and across oceanic depths.

First record of Mysidopsis gemina Price, Heard & Vargas, 2019 (Crustacea, Peracarida, Mysida, Mysidae) on the west coast of Mexico

Mysidopsis gemina Price, Heard & Vargas, 2019, a species of mysid shrimp recorded for Pacific Costa Rica, was collected in western Mexico on October 19th, 2022, at the entrance of the Gulf of California. This is the first record north of Costa Rica and it represents a distribution range extension to the north of approximately 13 degrees of latitude. A comparison of the diagnostic morphological features of the Costa Rican and Mexican specimens is given.

Succession of the sessile benthic community at a coral reef restoration site.

Introduction: Ecosystem restoration facilitates ecological succession. When a coral reef experiences a disturbance, the community of sessile benthic organisms can follow a successional trajectory that favors the dominance of coral or a change of state to an ecosystem dominated by algae. 
 Objective: To better understand the impact of coral transplants on succession of the sessile benthic community, this study 
 Methods: To measure and monitor the coral cover (cm2) of Pocillopora spp., and the composition of the associated benthic community, experimental and control coral reef patches were established at the coral restoration site in Golfo Dulce, South Pacific Costa Rica. Thirty Pocillopora spp. colonies were attached to nails on the substrate in an experimental patch. The control coral patch contained nails with non-transplanted colonies. Both treatments were photographed monthly during a period of eight months. Changes in the coverage of coral and other sessile benthic organisms were measured from the images and compared over time between the experimental and control patches. 
 Results: The coral transplants experienced bleaching events in August through September 2019 and January through February 2020. The first bleaching event possibly due to sedimentation, and the second to high temperatures. By the end of the experiment, 83 % of the colonies had survived. The live colonies grew significantly following transplantation; > 67 % of their initial coverage area after eight months. In the experimental patch, the areas of Pocillopora spp., coralline crustose algae (CCA), and cyanobacteria increased while the area of algal turf decreased. The increase in coral coverage and CCA, and decrease in algal turf in the experimental patch could be due to herbivores attracted to transplants. The increase in cyanobacteria in the experimental patch could be the result of higher temperatures and may have been a factor in the death of colonies. 
 Conclusions: The transplantation of Pocillopora spp. colonies in Golfo Dulce changed the early successional trajectory of the sessile benthic community to favor the dominance of coral dominance in the experimental patch. These results may be useful in informing expectations for future restoration efforts.

First record of the Fiddler Crab, Minuca osa from the Eastern Montijo Gulf, Panama

Minuca osa had been previously thought to be endemic to Pacific Costa Rica (Golfo Dulce). However, specimens fitting the description were sampled in April 2021 and August 2022 in two sites in the Eastern Montijo Gulf, Panama. Based on the morphological character correspondence between the specimens collected and the original species description, it can be concluded that Minuca osa is also present in the Eastern Montijo Gulf.

Studies on Neotropical Phasmatodea XXV: Revision of Pterinoxylus Serville, 1838, with the descriptions of two new species from Costa Rica. (Phasmatodea: Oriophasmata: Cladomorphinae: Pterinoxylini)

The genus Pterinoxylus Serville, 1838 is redescribed and revised at the species level. It is distributed throughout most of Central America, the northern half of South America and also has one species on the Lesser Antilles. Detailed descriptions, notes on intraspecific variability and illustrations are provided for all six known species. Keys are presented to distinguish males, females and eggs. Two new species are described from Costa Rica: P. cocoense n. sp. from both sexes and the eggs and P. speciosus n. sp. from both sexes. The female of P. perarmatus (Redtenbacher, 1908) is described and illustrated for the first time, as are the eggs of the type-species P. eucnemis Serville, 1838 and P. perarmatus (Redtenbacher, 1908). The external morphology of all species shows considerable intraspecific variability, which is discussed and illustrated. While P. cocoense n. sp. is an endemic and the only stick insects that has so far become known from Cocos Island a small island some 550 km off the Costa Rican Pacific coast, all other species appear to have fairly wide distributional ranges. Maps show the distributions of all six known species. Type-specimens of the two newly described species are deposited in the collections of MNCR-A (Costa Rica) and Zoologisches Museum und Universität, Hamburg, Germany (ZMUH).

Sexual dimorphism in the methane seep-dwelling Costa Rican yeti crab Kiwa puravida (Decapoda: Anomura: Kiwaidae)

Deep-sea chemosynthesis-based ecosystems support unique biological communities, but human impacts are an increasing threat. Understanding the life-history traits of species from deep-sea chemosynthesis-based ecosystems can help to develop adequate management strategies, as these can have impacts on ecological responses to changes in the environment. Here we examined the occurrence of sexual dimorphism in the yeti crab Kiwa puravida, an endemic species from the Costa Rican Pacific margin that aggregates at active methane seeps and depends on chemosynthetic bacteria for nutrition. The two morphological features examined included the claws, suspected to be under sexual selection and used for defense, and the carpus of the second pereopod not suspected to be under sexual selection. A total of 258 specimens, 161 males, 81 females, 16 juveniles, were collected from Mound 12 at 1,000-1,040 m depth in 2017 and 2018 and analyzed. We found that males have larger and wider claws than females, while there were no differences in carpus length. These results suggest that claw weaponry is under sexual selection in K. puravida, which is probably related to the mating system of this deep-sea species. This is the first attempt to study the reproductive biology of K. puravida, and additional observations will be necessary to shed more light on this matter.

Up the hill and under the canopy: Lidar applications for assessing issues of monumentality and socioeconomic status in Lomas Entierros, Costa Rica

Recent lidar, survey, and excavation have facilitated the mapping of the Lomas Entierros archaeological site in Central Pacific Costa Rica, with a main occupation and construction dating from 800–1200 CE. The data document the architectural pattern of the site, which differs from other monumental sites known in the region in terms of the distribution of architectural features. The proposed regional architectural assemblage of a main mound, plaza and causeway as an epicenter of elite activity is not present at Lomas Entierros, where elites are located at the hilltop, on the northwestern sector of the site. Rather, the distribution at Lomas Entierros suggests factors such as elevation, visibility, and defensibility were more socially valued for the location of elite residences.Lay summary:The Lomas Entierros archaeological site flourished from 800–1200 CE in Central Pacific Costa Rica. However, heavy forest coverage has hindered traditional archaeological work for decades. Lidar technology now permits the mapping of the settlement’s architecture by deleting the vegetation layers collected in the data. Through the creation of digital models, survey, and excavation we have documented the architectural pattern of the site and compare it to other known settlements in the area. Lomas Entierros presents a different design that values elements of elevation, visibility, and defensibility. Understanding such differences permits us to register the variability of expressions in the use of space, construction patterns, power, and adaptation to the environment in past societies.

Hematological reference values for Alouatta palliata (Primates: Atelidae) and Cebus imitator (Primates: Cebidae) from the Pacific Coast of Costa Rica

Introduction: Wildlife hematological patterns are fundamental for health monitoring, and allows elucidating variations both within and between populations. Among these, hematological parameters are particularly valuable to evaluate the health status of neotropical primate species in the wild. Objective: To define hematological reference values for two species of monkeys in Costa Rica. Methods: During 2014, we collected blood samples from free-ranging mantled howler monkeys, Alouatta palliata (17 females, 18 males) and white-faced capuchin monkeys, Cebus imitator (5 females, 7 males) in seven localities of the Costa Rican Pacific coast. Results: For both species, the hematological values were higher in males, and howler monkey populations differed significantly except for platelets. Conclusions: These hematological values, which differ by sex and locality, will help evaluate the health status of these neotropical primate populations.

The First Ex-Situ Germination and Dispersal Mechanisms of the Rare, Critically Endangered Tree, Pleodendron costaricense

Background and Research aims The extinction of relict and rare tree species is accelerated by habitat loss and climate change. Pleodendron costaricense is a critically endangered tree, with only four mature individuals known in Southern Pacific Costa Rica. With the discovery of three additional trees, we set out to learn more about P. costaricense’s natural history and attempt the first successful germination. Methods We collected fruits from two trees and carried out preliminary germination trials in a nursery at the study site. We also used camera traps in one of the fruiting mother-trees to understand natural dispersal mechanisms of the species. Results Although plagued by excessive levels of invertebrate predation, we were able to germinate and produce 59 saplings ready for restoration planting. Five mammal species were detected on the camera traps feeding on the fruits, along with one primate potentially using the fruits as a topical medicine. Conclusion P. costaricense can be propagated ex-situ, potentially with greater success using stimulating hormones. To improve production rates, future efforts should focus on the protection of germinating seeds and saplings from seed predators. We also identified numerous potential natural mammalian seed dispersers, mostly in the family Procyonidae. Implications for Conservation Given the propagation knowledge we have developed, the active restoration efforts of the saplings by Osa Conservation to help increase population numbers, and the strict protection of the two fruiting mother trees, there is now the possibility to attain a positive conservation outcome for this critically endangered species.

Revision of Chloeia Savigny in Lamarck, 1818 from tropical American seas (Annelida, Amphinomidae).

The species of Chloeia Savigny in Lamarck, 1818 include some of the most colorful amphinomid annelids in tropical seas. Their pigmentation patterns can be diagnostic but because some pigments may fade after ethanol preservation, they have been disregarded as useful taxonomic characters. In this contribution we revise the tropical American species of Chloeia, and we confirm stability of pigmentation patterns, the presence of cirriform branchiae along a few anterior chaetigers, and emphasize the size of eyes and of ventral cirri as diagnostic characters. Five species are redescribed and two ones are newly described; the redescribed species are C. entypa Chamberlin, 1919 from Western Mexico, C. euglochis Ehlers, 1887 from the Grand Caribbean (reinstated), C. pinnata Moore, 1911 from Southern California (extended southwards in Western Mexico), C. pseudeuglochis Augener, 1922 from Pacific Costa Rica (includes several records for a colorful shallow water species in the Eastern Pacific), and C. viridis Schmarda, 1861 from the Grand Caribbean, which is restricted to specimens having a single, dorsal longitudinal T-shaped band. New species are Chloeia nuriae sp. n. from the Gulf of California, and C. paulayi sp. n. from the Gulf of Mexico . Two other species previously recorded for the region, C. conspicua Horst, 1910 and C. flava (Pallas, 1766) are briefly characterized in order to avoid future misidentifications. Further, C. candida Kinberg, 1857 from the Virgin Islands, is regarded as indeterminable. A key to identify tropical American species of Chloeia is also included.

Interception and Redistribution of Precipitation by Parkinsonia aculeata L.: Implications for Palo Verde National Park Wetlands, Costa Rica

Seasonal wetlands in the tropics are important habitats for local and migratory bird species. In the northwestern Pacific of Costa Rica, Palo Verde National Park has one of the most important seasonal wetlands of Central America. The management history of this wetland has shown the impact of invasive plant species such as Parkinsonia aculeata L. whose cover extension and canopy structure impact not only the ecological niches of bird species, but also the wetland hydrology. A 300 m2 plot was established in a P. aculeata stand to evaluate the role of P. aculeata on the partitioning and redistribution of precipitation. Gross precipitation (PGr), throughfall (PTF) and stemflow (PSF) were measured on a daily basis to determine the interception of precipitation (PI) and net precipitation (PNet). A total of 43 precipitation events were sampled during the wet season of 2003. We measured 530.5 mm of PGr and 458 mm of PTF, with an average sampling error of 0.7 mm or 6.1%. Canopy storage capacity was estimated at 1.47 mm, throughfall 88.73%, stem flow 2.63% and a total interception of 8.64%, with a PNet coefficient of 0.9475. The relationships between gross precipitation (PGr) with throughfall (PTF), stemflow (PSF) and net precipitation (PNet) were evaluated using linear regression models. P. aculeata showed to have one of the highest net precipitation and lowest precipitation interception among small trees.

Predictive habitat suitability models to aid the conservation of elasmobranchs in Isla del Coco National Park (Costa Rica)

Worldwide there is increasing concern for elasmobranch species given that their biological and ecological characteristics make them highly vulnerable to fishing pressure. The disappearance of these species could affect the structure and function of marine ecosystems, which would induce changes in trophic interactions at the community level. For effective conservation and management of elasmobranchs detailed knowledge of their habitat preferences is essential. Yet, there is a poor understanding of their spatial ecology. Isla del Coco National Park is an oceanic island in Pacific Costa Rica and renowned for being a sanctuary for migratory pelagic species, such as elasmobranchs and other non-migratory species. However, the abundance of many of these species has been rapidly declining over the last decades as a result of overexploitation (legal and illegal fishing). Within this context, Generalized Additive Models were performed to investigate the environmental preferences of eight elasmobranch species in Isla del Coco National Park using six predictors (i.e., sea surface temperature, salinity, chlorophyll-a concentration, bathymetry, distance from the coast and slope). Results demonstrate similar habitat preferences based on distance from the coast, slope and chlorophyll, which indicates that elasmobranchs prefer shallow waters near the island with varying degrees of slope. This study helps to identify both some of the hotspots for elasmobranchs biodiversity in Isla del Coco National Park. This approach provides an essential and relatively easy tool, such as predictive distribution maps, to increase our knowledge of marine habitats in Isla del Coco to better manage them and other offshore marine protected areas.

Soft corals (Cnidaria, Alcyonacea) from the Gulf of Nicoya estuary, Pacific of Costa Rica: a checklist

Introduction: The Gulf of Nicoya is the most important estuary on the Pacific coast of Costa Rica. Information on the presence of soft corals is scattered in the literature and in museum collections. Objective: To provide a list of soft corals reported for the estuary. Methods: We compiled the literature (2002-2020) and of the specimens deposited at the Museum of Zoology, University of Costa Rica. Results: Thirty species have been reported for the estuary (Clavulariidae, Gorgoniidae and Plexauridae). Most were collected on the eastern coast of the Nicoya Peninsula, and several species were described based on estuary specimens. Conclusion: The 30 species represent 79 % of those reported for Costa Rica. Despite this relatively high percentage, the sampling effort has been modest and other sites within the estuary should be explored.

The devil is coming: Feeding behavior of juvenile Munk’s devil rays (Mobula munkiana) in very shallow waters of Punta Descartes, Costa Rica

Introduction: Identifying critical habitats for vulnerable elasmobranch species is crucial for effective conservation measures. The Munk’s devil ray (Mobula munkiana) is endemic to the Eastern Pacific, but yet little is known about its biology, ecology, and habitat use. As filter feeders, it is assumed that this species concentrates at high-productive upwelling regions, such as the Costa Rican Dome. Like many elasmobranchs, its populations are highly depleted and require urgent information to inform better conservation measures.
 Objective: The study was conducted to gain information on a unique behavior observed in juvenile M. munkiana, so further information can be provided on early life stages of this vulnerable species.
 Methods: From June to September 2017 and in August 2018, the feeding behavior of juvenile Mobula munkiana was observed in two shallow bays located at Punta Descartes, North Pacific Costa Rica. Individuals were captured using a non-lethal method to obtain data on size, weight, and sex distribution. Plankton samples (n = 100) were taken at both bays throughout the months to infer diet composition.
 Results: Munk’s devil rays showed a repetitive swimming movement parallel to the beach, feeding exclusively in the shallow breaking zone of the low tide waves at depth <50cm. A total of 12 M. munkiana (11 live and one found dead) indicated a juvenile feeding aggregation ranging from 490 – 610mm in disk width and 1400 – 2300gr in weight. The sex ratio (males to females) was 3:1. Zooplankton of the order Mysidacae was found in the highest abundance in the breaking zone.
 Conclusions: The specific behavior and seasonal occurrence of juvenile Munk’s devil rays in this area seem to be driven by prey abundance. More research is needed to conclude the presence of reproductive adults at deeper depths and the year-round habitat use of Punta Descartes. The area is threatened by unsustainable development and requires realistic management strategies to guarantee the survival of vulnerable species and their critical habitats.

Venomics of the poorly studied hognosed pitvipers Porthidium arcosae and Porthidium volcanicum

We report the first proteomics analyses of the venoms of two poorly studied snakes, the Manabi hognosed pitviper Porthidium arcosae endemic to the western coastal province of Manabí (Ecuador), and the Costa Rican hognosed pitviper P. volcanicum with distribution restricted to South Pacific Costa Rica and western Panamá. These venom proteomes share a conserved compositional pattern reported in four other congeneric species within the clade of South American Porthidium species, P. nasutum, P. lansbergii, P. ophryomegas, and P. porrasi. The paraspecific immunorecognition profile of antivenoms produced in Costa Rica (ICP polyvalent), Perú (Instituto Nacional de Salud) and Brazil (soro antibotrópico pentavalente, SAB, from Instituto Butantan) against the venom of P. arcosae was investigated through a third-generation antivenomics approach. The maximal venom-binding capacities of the investigated antivenoms were 97.1 mg, 21.8 mg, and 25.7 mg of P. arcosae venom proteins per gram of SAB, ICP, and INS-PERU antibody molecules, respectively, which translate into 28.4 mg, 13.1 mg, and 15.2 mg of total venom proteins bound per vial of SAB, ICP, and INS-PERU AV. The antivenomics results suggest that 21.8%, 7.8% and 6.1% of the SAB, ICP, and INS-PERU antibody molecules recognized P. arcosae venom toxins. The SAB antivenom neutralized P. arcosae venom's lethality in mice with an ED50 of 31.3 mgV/g SAB AV. This preclinical neutralization paraspecificity points to Brazilian SAB as a promising candidate for the treatment of envenomings by Ecuadorian P. arcosae. Biological significanceAssessing the preclinical efficacy profile of antivenoms against homologous and heterologous medically relevant snake venoms represents an important goal towards defining the biogeographic range of their clinical utility. This is particularly relevant in regions, such as Mesoamerica, where a small number of pharmaceutical companies produce antivenoms against the venoms of a small number of species of maximum medical relevance among the local rich herpetofauna, leaving a wide range of snakes of secondary medical relevance, but also causing life-threatening human envenomings without nominal clinical coverage. This work is part of a larger project aiming at mapping the immunological characteristics of antivenoms generated in Latin American countries towards venoms of such poorly studied snakes of the local and neighboring countries' herpetofauna. Here we report the proteomics characterization of the Manabi hognosed pitviper Porthidium arcosae endemic to the western coastal province of Manabí (Ecuador), and the Costa Rican hognosed pitviper P. volcanicum with distribution restricted to southwestern Costa Rica, the antivenomics assessment of three bothropoid commercial antivenoms produced in Costa Rica, Perú, and Brazil against the venom components of P. arcosae, and the in vivo capacity of the Brazilian soro antibotrópico pentavalente (SAB) from Instituto Butantan to neutralize the murine lethality of P. arcosae venom. The preclinical paraspecific ED50 of 31.3 mg of P. arcosae venom per gram of antivenom points to Brazilian SAB as a promising candidate for the treatment of envenomings by the Manabi hognosed pitviper P. arcosae.