Two new Campylaimus species from Arroyo Pareja, Buenos Aires province and one new species and one new record of Campylaimus from Puerto San Julián, Chubut province are described. The three species are characterized by the shape of the copulatory apparatus of the male and the presence of precloacal papillae. Campylaimus bonariensis sp. nov. has slender and arcuate spicules, with well-developed cephalization at the proximal end, tubular gubernaculum and three precloacal papillae; Campylaimus arcuatus sp. nov. has curved spicules, with well-developed cephalization at the proximal end, gubernaculum with dorso-caudally directed apophysis and five precloacal papillae; Campylaimus patagonicus sp. nov. has slender and arcuate spicules without proximal cephalization, gubernaculum with dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Campylaimus and an identification key to species based on male characters are given.
Summary:The embryogenesis of Ovalipes trimaculatus, a member of the highly valued portunid swimming crabs, was studied under nearly constant temperature (13±1°C), salinity (33) and photoperiod (14 h light:10 h dark) conditions. A five-stage scale of embryonic development was defined for the species. Time required to complete development averaged 35.7±2.11 days, showing no significant differences between embryos located in inner, middle and outer portions of the egg mass. The egg chorion was rounded and showed the highest growth in diameter between stages I (morula-blastula-gastrula) and II (primordium of larval structure) and between stages III (appendage formation) and IV (eye formation). Results reported here provide a baseline for optimizing hatchery operations and useful information for management purposes.Keywords: crustacean; crabs, aquaculture; Ovalipes trimaculatus; embryology.Desarrollo embrionario del cangrejo nadador Ovalipes trimaculatus (Decapoda: Brachyura: Portunoidea) Resumen: Se estudió la embriogénesis del cangrejo nadador Ovalipes trimaculatus, miembro de la familia de portúnidos altamente valorados, bajo condiciones constantes de temperatura (13±1°C), salinidad (33) y fotoperíodo (luz 14h:10h oscuridad). Se definió una escala de cinco etapas de desarrollo embrionario para la especie. El tiempo necesario para completar el desarrollo es de 35.7±2.11 días, sin mostrar diferencias significativas entre embriones ubicados en porciones interior, media y exterior de la masa de huevos. Los huevos son esféricos y presentan mayor crecimiento en diámetro entre las etapas I (mórula -blástula -gástrula) y II (primordio de estructuras larvarias) y entre las etapas III (formación de apéndices) y IV (formación de los ojos). Los resultados aquí presentados proporcionan la base para la optimización del cultivo y brindan información útil para el manejo de la especie.Palabras clave: crustáceos; cangrejos; acuicultura; Ovalipes trimaculatus; embriología.Citation/Como citar este artículo: Martelli A., Tapella F., González-Pisani X., Dellatorre F., Barón P.J. 2016. Embryonic development of the southern surf crab Ovalipes trimaculatus (Decapoda: Brachyura: Portunoidea). Sci. Mar. 80(4): 499-509.
Two new free-living marine nematodes of the family Oxystominidae are described from San Antonio Bay (Río Negro) and San José Gulf (Chubut). Litinium australis sp. n., is characterized by having a rounded tail, by the first and second crown of cephalic setae with different lengths, gubernaculum with apophysis and by the presence of at least four precloacal papillae; Thalassoalaimus nestori sp. n., is characterized by having a conical tail, cephalic setae equal in length, gubernaculum with rounded and dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Thalassoalaimus and a key to species are given.
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