External morphology of eyes and Nebenaugen of caridean decapods–ecological and systematic considerations

Most caridean decapods have compound eyes of the reflecting superposition kind, and additionally some possess an accessory eye-like organ of unknown function, also referred to as the nebenauge.We examined 308 caridean genera to assess the general morphology of the eye, rostrum length, eye diameter and the presence or absence and, when present, the diameter of the nebenauge.We have attempted to relate these data to ecological and taxonomic considerations.We consider there to be 6 distinct eye types based on the margin between the eyestalk and cornea. The presence of nebenaugen appears to be generally linked to an active lifestyle, as evidenced by the fact that species that have nebenaugen tend to have larger eyes and are more likely to have a distinct rostrum.We suggest that the inconsistencies in its presence/absence under both systematic and ecological lenses may indicate that when present it has various roles relating to behavioural and physiological rhythms

Shrimps (Crustacea, Decapoda, Caridea) associated with gorgonians at the coast of Senegal

Symbioses are common in the marine environment. Some taxa appear to be particularly prone to be involved in associations. Crustaceans probably form more associations with other classes than any other marine animals (Ross 1983), crustacean – cnidarian associations being particularly common (Patton 1967). Gorgonianassociated decapods have been described from both sides of the Atlantic (e.g. Spotte et al. 1994, 1995, Wirtz & d´Udekem d´Acoz 2001, Wirtz et al. 2009). Gorgonians were therefore searched for associated decapods during three dives in the area of NGor, Senegal, i.e. at the western tip of Africa.info:eu-repo/semantics/publishedVersio

Linking eye design with host symbiont relationships in pontoniine shrimps (crustacea, decapoda, palaemonidae)

Symbiosis is prevalent in the marine environment with many studies examining the effects of such interactions between host and symbiont. Pontoniine shrimps are a group whose ecology is characterised by symbiotic interactions. This investigation examines the gross morphology of Pontoniinae compound eyes and superficial optical parameters with reference to their symbiotic relationship or lifestyle category; free-living, ectosymbiont, endosymbiont (bivalves) or endosymbiont (non-bivalves). The eye morphologies of free-living and ectosymbiotic species are very similar, yet differ from both forms of endosymbiotic species. Endosymbionts have significantly smaller and simpler eyes with larger facets and bigger interommatidial angles and eye parameters for increased sensitivity levels. However bivalve endosymbionts form an intermediary group between non-bivalve endosymbionts and ectosymbionts as a result of their more active lifestyle. The accessory eye or "nebenauge", although of uncertain function, commonly occurs in free-living Pontoniinae species but rarely in endosymbionts apart from in more primitive species. The variation in morphology reflects tensions between functional requirements and ecological pressures that have strongly influenced eye design in Pontoniinae. © 2014 Dobson et al

The carcinological oeuvre of Charles Spence Bate (1819–1889): Checklist of species and genera, dates of publication, and a list of publications (Crustacea: Amphipoda, Cirripedia, Cumacea, Decapoda, Tanaidacea)

Charles Spence Bate (1818–1889) was one of the more influential mid to late 19th century crustacean taxonomists, with broad interests spanning several taxonomic groups, such as Amphipoda and Decapoda. Despite several contemporary obituaries, no full publication list for him has ever been assembled. In the present contribution, we provide a complete listing of publications and all species- and genus-level crustacean taxa described by Spence Bate, and indicate their current status. Corrections to publication dates are listed, and several decisions are made to stabilise crustacean nomenclature. In a scientific career spanning almost 50 years (1850–1889), Spence Bate described a total of 402 species and 70 genera in Decapoda, 181 species and 46 genera in Amphipoda, as well as eight genera and eight species of Cumacea, four genera and 16 species of Isopoda, three of Tanaidacea and one of Cirripedia. Of these, 36.2% of species and 45.7% of genera are still considered as the accepted names for their taxa today

Gossea Spence Bate & Westwood, 1862 (Amphipoda) and Gossea Agassiz, 1862 (Cnidaria, Hydrozoa): reversal of presumed precedence and review of the complicated nomenclatural history

Gossea Agassiz, 1862 (Cnidaria: Hydrozoa) and Gossea Spence Bate & Westwood, 1862 (Crustacea: Amphipoda) are homonyms and Agassiz’s genus has long been considered the senior name. Discovery of copyright information for Agassiz’s book shows that the presumed order of precedence is incorrect and that Spence Bate & Westwood’s genus name is the senior homonym. A detailed history of both genera is given with the recognition that Apherusa Walker, 1891 is an unnecessary replacement name for Gossea Spence Bate & Westwood, 1862 and that Octobulbacea Zamponi, 1983, as the only available junior synonym, is the name that should be used for Gossea Agassiz, 1862. Gossea Agassiz, 1862 (Cnidaria: Hydrozoa) und Gossea Spence Bate & Westwood, 1862 (Crustacea: Amphipoda) sind Homonyme und die Gattung von Agassiz gilt seit langem als der älteste Name. Die Entdeckung von Urheberrechtsinformationen für das Buch von Agassiz zeigt jedoch, dass die vermutete Rangfolge nicht korrekt ist, und dass der Gattungsname von Spence Bate & Westwood das älteste Homonym ist. Eine detaillierte Geschichte beider Gattungen wird dargestellt, mit der Erkennung dass Apherusa Walker, 1891 ein unnötiger Ersatzname für Gossea Spence Bate & Westwood, 1862 ist, und dass Octobulbacea Zamponi, 1983 als einziges verfügbares jüngeres Synonym für Gossea Agassiz, 1862 verwendet werden sollte

A new shallow-water species of the rare shrimp genus Bresilia from Cabo Verde (Crustacea, Decapoda, Bresiliidae)

A new species of the rare shrimp genus Bresilia is described and illustrated from shallow-water lava tubes in Cabo Verde. Characteristics differentiating the new species from its three known Atlantic congeners are listed and discussed. Scanning electron images (SEM) are provided of the peculiar chela ornamentation of the first pereiopod in the genus

Two new species of Onycocaris (Decapoda, Palaemonidae) from the central Pacific

Two new species of the genus Onycocaris are described, based on single specimens from Fiji and Moorea respectively. Onycocaris iti sp. nov. is closely related to the relatively widespread species, O. seychellensis Bruce, 1971; whilst O. brucei sp. nov. is a pseudo-cryptic species allied to O. quadratophthalma (Balss, 1921)

Synalpheus pinkfloydi sp. nov., a new pistol shrimp from the tropical eastern Pacific (Decapoda: Alpheidae)

A new, conspicuously coloured species of the alpheid genus Synalpheus Spence Bate, 1888, is described based on material collected on the Pacific coast of Panama. Synalpheus pinkfloydi sp. nov. is closely related to the western Atlantic S. antillensis Coutière, 1909, the two taxa being transisthmian, cryptic sister species. Both species are characterised by the distal areas of their major and minor chelae coloured in an intense, almost glowing pink-red. The morphological differences between S. pinkfloydi sp. nov. and S. antillensis Coutière, 1909 are subtle, being limited to the slightly different proportions of the merus of both chelipeds, distodorsal armature of the major cheliped merus, relative length of the antennal scaphocerite, and body size. However, they are genetically different with a 10.2% sequence divergence in COI. Based on molecular clock estimates, these transisthmian taxa diverged around 6.8–7.8 mya, i.e. well before the final closure of the Isthmus of Panama 2.5–3 mya

Preliminary observations on the mandibles of palaemonoid shrimp (Crustacea: Decapoda: Caridea: Palaemonoidea)

The mandibles of caridean shrimps have been widely studied in the taxonomy and functional biology of the group. Within the Palaemonoidea the mandibles reach a high level of structural diversity reflecting the diverse lifestyles within the superfamily. However, the majority of studies have been restricted to light microscopy, with the ultrastructure at finer levels poorly known. This study investigates the mandible of nine species belonging to six of the recognised families of the Palaemonoidea using SEM and analyses the results in a phylogenetic and dietary framework. The results of the study indicate that little phylogenetic information is conveyed by the structure of the mandible, but that its form is influenced by primary food sources of each species. With the exception of Anchistioides antiguensis, all species examined possessed cuticular structures at the distal end of the pars molaris (molar process). Five types of cuticular structures are recognised herein, each with a unique form, but variable in number, placement and arrangement. Each type is presumed to have a different function which is likewise related to diet

Insights into the morphology of symbiotic shrimp eyes (Crustacea, Decapoda, Palaemonidae); the effects of habitat demands

Morphometric differences in the optical morphology of symbiotic palaemonid shrimps can be observed among species symbiotic with different host organisms. Discriminant functional analysis revealed three distinct groups within the species examined. Of these, bivalve symbionts appear to have an eye design that is solely unique to this host-symbiont grouping, a design that spans across multiple genera of phylogenetically unrelated animals. Although some taxonomic effects may be evident, this does not explain the difference and similarities in eye morphology that are seen within these shrimps. Therefore evolutionary pressures from their host environments are having an impact on the optical morphology of their eyes however, as indicated by host-hopping events there ecological adaptations occur post host invasion