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Two double-labelling methods, Tunel + propidium iodide and Annexin V-FITC + propidium iodide, have been tested to diagnose cell degradation processes in N1-N2 nauplius stages produced by spawning females of the copepod Calanus helgolandicus fed either non-toxic (PRO: control) or toxic (TR1) diets under laboratory conditions. Observation of labelled samples with a confocal laser-scanning microscope revealed that the maternal-food effect, following absorption of the toxic diet, induced cell apoptosis and necrosis in 80-100% of the offspring, which sooner or later died. Similar cell damages were also observed in 18-50% of the nauplii produced by females incubated in filtered seawater. Such cell degradation processes and high mortality were not observed in nauplii produced by females fed the non-toxic diet. Our protocols allowed detection of cell degradations before death of unhealthy larvae, preferentially with a confocal microscope or a conventional visible-fluorescent-light microscope.

The generic positions of the 29 Indo-West Pacific species currently placed in Rochinia A. Milne-Edwards, 1875, sensu lato, are addressed, in an attempt to establish a more phylogenetically coherent classification for these spider crabs. Twenty-five Indo-West Pacific species are referred to a redefined Samadinia Ng & Richer de Forges, 2013. Three species are transferred to Laubierinia Richer de Forges & Ng, 2009, Pugettia Dana, 1851, and Oxypleurodon Miers, 1885, respectively. Rochinia kagoshimensis (Rathbun, 1932) and a new species from the South China Sea are assigned to a new genus. The generic status of four Atlantic species of Rochinia is also discussed. [ABSTRACT FROM AUTHOR]

For the century to 2018, only one species of the deep-water porter crab Gordonopsis Guinot & Richer de Forges, 1995 (Brachyura, Homolidae), the type species, G. profundorum (Alcock & Anderson, 1899), was known, and only from a handful of specimens from the Indian Ocean. In 2019, two species were described from the eastern Indian and western Pacific Oceans. The present revision of available material, most of which was only collected in the last decade, adds five new species to the genus. This explosion in species numbers demonstrates just how poor our understanding is of deep-sea habitats and their constituent fauna. [ABSTRACT FROM AUTHOR]

The French MUSORSTOM expeditions (now Tropical Deep-Sea Benthos), have successfully collected since 1976 rich samples of large, benthic crustaceans using oceanographic vessels to depths of about 5,000 m. The ship-based collecting techniques and gear used by these expeditions are described. These include the use of echosounders, dredging, trawling, and trapping. Also discussed are techniques for onboard specimen sorting and photography. [ABSTRACT FROM AUTHOR]

The taxonomy of spider crabs of the genus Maja Lamarck, 1801, is revised, and a total of 36 species in 10 genera are now recognised from the eastern Atlantic, Mediterranean and Indo-West Pacific. The present revision describes seven genera and 17 species as new. Two genera previously synonymised under Maja: Paramaya De Haan, 1837, and Paramaja Kubo, 1936, are here treated as valid taxa. The confused nomenclature of Cancer cornutus Linnaeus, 1758, is resolved, and the name replaces Maja capensis Ortmann, 1894, and Mamaia queketti Stebbing, 1908. All genera and species are diagnosed and figured, and keys are provided for their identification. [ABSTRACT FROM AUTHOR]

Relatively few studies have been done to define or assess rarity in the marine environment. Published studies have focused on shallow-water and intertidal habitats, and the available information appears to reflect the same pattern observed in terrestrial environments, i.e., that there are many rare species and few common species in any one given area. However, our studies of the abundance of new and/or supposedly rare taxa of decapod crustaceans from the deep, steep slopes of the island of Balicasag, in the central Philippines, have raised questions on how rarity should be defined in marine invertebrates. Examples of such supposedly rare species of crabs and lobsters (Crustacea: Decapoda) are presented here. That these animals come from deep, steep slopes, a relatively under-studied habitat, highlights the major gaps in current knowledge of marine biodiversity that are in part due to the inadequacy of both traditional and high technology sampling methodologies and the limited habitat types that the former can target. Low-technology, artisanal tangle nets have proved to be an optimal capture technique for deep-water decapod crustaceans on deep, steep slopes; many new taxa have been discovered and, in other cases, perceptions of rarity and endemicity have been corrected. [ABSTRACT FROM AUTHOR]

In 2005, the EBISCO oceanographic campaign collected numerous large ostracods in the Coral Sea, off southwest New Caledonia. These ostracods belong to a new species, Azygocypridina brynmawria, and differ from the morphologically similar Azygocypridina lowryi in the color of the soft parts and details of the morphology of the second antenna, furca, and terminal tooth of the seventh limb, as determined by light microscopy and scanning electron microscopy (SEM). Included is a discussion of the unique color and locality of these organisms. [ABSTRACT FROM AUTHOR]

Presents a study which investigated the ultrastructure of the spermatozoa of hymenosomatidae (Crustacea: Brachyura) and family relationships. Indication of distinctive characteristics among spermatozoa of hymenosomatidae to those of other eubrachyurans investigated; Specification of those characteristics; Implication of study's findings.

A total of 17 species, in 14 genera of majids have been examined for sperm ultrastructure. The present account describes the sperm of six of these species, in two subfamilies: Pisinae—Sphenocarcinus orbicutalus and Sphenocarcinus stuckiae and Inachinae—Cvnonmia furici, Grypacheus hyalinure. Platymaia rebierei and Macropodia longirostris. M. longirostris has the only eubrachyuran sperm in which the acrosome is known to depart radically from a subspheroidal form. The acrosome is semilunar in shape and is bordered by a very thin layer of cytoplasm and an unusually uniform, narrow band of chromatin. The apical surface of the acrosome is almost flat, though slightly concave, whereas the posterior surface forms a hemisphere, and is almost completely occupied by the thin. centrally perforate, electron dense operculum. The bulk of the acrosome consists of a homogeneous. moderately electron dense outer acrosome zone. This surrounds a small inner acrosome zone internal to which is an ellipsoidal, pale perforatorium capped by a central acrosome zone. Majid sperm arc distinguished by a flattened and/or centrally depressed operculum; a further characteristic is that the pointed perforatorium is relatively short and frequently does not reach the operculum. They vary inter aim with regard to presence or absence of a posterior median process and, apparently. of centrioles and of microtubules in the nuclear arms and in the number of these arms. Perforation of the operculum, seen in the Pisinae, is not constant in the Inachinae. Spermatozoal ultrastructure offers no certain support for a close relationship of majids with parthenopids or hymenosomatids. [ABSTRACT FROM AUTHOR]