Producción de huevos en Eurypodius latreillii Guérin, 1828 (Decapoda: Majidae) en el Estrecho de Magallanes, sur de Chile

Egg production and reproductive investment were studied in the spider crab Eurypodius latreillii from the Straits of Magellan, southern Chile. A total of 66 ovigerous females were analyzed, ranging in size from 29.0 to 62.9 mm carapace length. E. latreillii produced up to 15886 embryos, and clutch size increased with maternal size. Initial egg size was large (0.162 mm3), and the embryo volume increase during the incubation period was 32 %. Brood mortality was substantial (83 %), and since egg volume increase could not compensate for the egg loss, average egg mass volume decreased considerably during embryogenesis. The average brood mass at laying accounted for 13 % of the maternal body mass (on a wet mass basis), and this value coincides with previous findings concerning energy allocation for egg production in other brachyuran crabs. In general, our data regarding E. latreillii correspond well with those from spider crab species inhabiting the northern hemisphere. The large egg size of E. latreillii compared with majids from other geographical regions may be an indication of a latitudinal gradient in the reproductive biology of majid crabs. Future studies with spider crabs from the southern hemisphere are desirable to substantiate this assumption.Se estudió la producción de huevos y la inversión reproductiva del cangrejo araña Eurypodius latreillii proveniente del Estrecho de Magallanes, sur de Chile. Se analizaron un total de 66 hembras ovígeras con un rango de tamaños entre 29,0 y 62,9 mm de longitud de caparazón. E. latreilli produjo hasta un máximo de 15886 embriones, y el número de huevos aumentó con el tamaño de la hembra. El tamaño inicial del huevo fue grande (0,162 mm3) y el aumento del volumen embrionario durante el período de incubación fue de 32 %. La mortalidad de huevos fue considerable (83 %), y como el aumento en el volumen de los huevos no pudo compensar la pérdida de huevos, el promedio del volumen de la masa de los huevos disminuyó de forma considerable durante la embriogénesis. La masa de huevos representó un 13 % de la masa corporal de la madre, y este valor coincide con observaciones previas sobre la asignación de energía para la producción de huevos en otros braquiuros. En general, nuestros datos sobre E. latreillii concuerdan con datos sobre especies del cangrejo araña del hemisferio norte. El tamaño grande de huevos de E. latreillii comparado con Majidae de otras regiones geográficas podría ser interpretado como una indicación de un gradiente latitudinal en la biología reproductiva de cangrejos májidos. Para corroborar esta interpretación se requerirían estudios futuros con cangrejos araña del hemisferio sur

Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns

This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa

Lipid and fatty acid composition of Antarctic shrimp eggs (Decapoda:Caridea)

Lipid and fatty acid composition of Antarctic shrimp eggs (Decapoda:Caridea)M. Graeve1, and I. S. Wehrtmann2(1)Alfred-Wegener-Institut für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany(2)Universidad de Costa Rica, Escuela de Biología, 2060 San Pedro-San José, Costa RicaAbstract. Eggs of the decapod shrimps, Chorismus antarcticus, Nematocarcinus lanceopes and Notocrangon antarcticus were taken to analysetheir morphometric, lipid and fatty acid composition. Almost all females carried undifferentiated eggs (stage I). The average number of recentlyextruded eggs was lowest in C. antarcticus with 163 eggs, and highest in Nematocarcinus lanceopes with 1,220 eggs, while Notocrangonantarcticus produced on average 350 eggs. The lipid content (% of dry mass) of the eggs was 18.8% for C. antarcticus, 14.3% for Notocrangonantarcticus and 18.1% for Nematocarcinus lanceopes. Dominant lipid classes in eggs of all species were phospholipids and triacylglycerols. Thestorage lipid, triacylglycerol, was slightly elevated in the eggs of Nematocarcinus lanceopes (mean of 52.7%) compared to the other two species.The fatty acid compositions of the decapod eggs were similar in the three species. Dominant fatty acids were 20:5(n-3), 18:1(n-9), 16:1(n-7), 16:0and 18:1(n-7), comprising 75.8-78.4% of total fatty acids. Among the species, the eggs of C. antarcticus had the highest proportions ofpolyunsaturated fatty acids (39.6%), dominated by 20:5(n-3), and the lowest percentage of monounsaturates (41.8%). The eggs ofNematocarcinus lanceopes and Notocrangon antarcticus contained almost the same proportion of polyunsaturated fatty acids (28.0% and28.4%, respectively), whereas Nematocarcinus lanceopes had the highest amount of monounsaturates due to the dominance of 18:1(n-9). Basedon our findings, we assume that eggs produced by polar decapod crustaceans do not contain substantially more lipids than related species fromtemperate or tropical regions. However, additional studies are necessary to substantiate any general conclusion about the relationship of egg lipidcontent and composition with climatic zones

Occurrences of Lithodid crabs (Crustacea: Decapoda: Lithodidae) from the Pacific coast of Costa Rica, Central America.

9 páginas, 3 figuras.[EN]Four species of lithodid crabs, Lithodes panamensis Faxon, 1893; L. wiracocha Haig, 1974; Paralomis diomedeae (Faxon, 1893); and P. papillata (Benedict, 1895), were collected during commercial cruises in the eastern Pacific Ocean off Costa Rica. Some remarks on their morphology and illustrations of some species are provided. A key to the species of the genus Lithodes from the eastern Pacific is included.[ES]Cuatro especies de cangrejos litódidos, Lithodes panamensis Faxon, 1893; L. wiracocha Haig, 1974; Paralomis diomedeae (Faxon, 1893); y P. papillata (Benedict, 1895), fueron recolectados en campañas comerciales en Costa Rica, Pacífico oriental. Se ilustran varias especies y se incluyen diversos comentarios sobre su morfología. Se incluye una clave para las especies del género Lithodes en el Pacífico oriental.This study was financially supported by the Vicerrectoría de Investigación, Universidad de Costa Rica (project number No 808-A8-209) and the Consejo Superior de Investigaciones Científicas (CSIC), Spain.Peer reviewe