A Comparative Study of the Genus Philinopsis Pease, 1860 (Aglajidae, Opisthobranchia)

ABSTRACT: A comparative study of Philinopsis gigliolii (Tapparone-Canefri, 1874); P. speciosa Pease, 1860; P. taronga (Allan, 1933); P. virgo (Rudman, 1968); P. troubridgensis (Verco, 1909); P. pilsbryi (Eliot, 1900); P. gardineri (Eliot, 1903); P. cyanea (Martens, 1879) indicates that they should be grouped in a separate genus, Philinopsis Pease, 1860, of the Aglajidae. The following taxonomic revision is suggested: P. taronga (Allan, 1933) = Chelidonttra aureopunctata Rudman, 1968; Philinopsis cyanea (Martens, 1879) = Doridium capense Bergh, 1907 = Aglaja iwasai Hirase, 1936; and Philinopsis gardineri (Eliot, 1903) = Chelidonura velutina Bergh, 1905, in part. It is also suggested that two senior synonyms of Philinopsis pilsbryi (Eliot, 1900), P. nigra Pease, 1860, and Doridium alboventralis Bergh, 1897, should be considered nomina oblita under Article 23 (b) of the International Code of Zoological Nomenclature. The reproductive system in which the spermoviduct is unbranched and does not open into the albumen gland is a major characteristic of the genus

On the Opisthobranch Genus Haminoea Turton & Kingston

A study was made of Haminoea zelandiae, H. solitaria, H. cymbalum, and H. crocata. The reproductive systems show a close similarity to that of Aplysia and lack of important anatomical differences show that Haloa and Lamprohaminoea are unnecessary genera. The mantle cavity, alimentary canal, and nervous system show the relationship of Haminoea to Atys and Smaragdinella

On Melanochlamys Cheeseman, 1881, a Genus of the Aglajidae (Opisthobranchia, Gastropoda)

ABSTRACT: Melanochlamys Cheeseman, 1881, long considered to be a synonym of Aglaja Renier, 1807, is shown to be a distinct genus of the Aglajidae differing from other genera in external body form, shape of shell, alimentary canal, and reproductive system. Specimens of the type species, M. cylindrica Cheeseman, 1881, are compared with M. lorrainae (Rudman, 1968), M. queritor (Burn, 1958), and M. diomedea (Bergh, 1893). It is suggested that Aglaja dubia O'Donoghue, 1929, A. ezoensis Baba, 1957, A. henri Burn, 1969, A. nana Steinberg & Jones, 1960, and A. seurati Vayssiere, 1926, also belong to Melanochlamys

Packaging and Delivery of Chemical Weapons: A Defensive Trojan Horse Stratagem in Chromodorid Nudibranchs

Background:Storage of secondary metabolites with a putative defensive role occurs in the so-called mantle dermal formations (MDFs) that are located in the more exposed parts of the body of most and very likely all members of an entire family of marine mollusks, the chromodorid nudibranchs (Gastropoda: Opisthobranchia). Given that these structures usually lack a duct system, the mechanism for exudation of their contents remains unclear, as does their adaptive significance. One possible explanation could be that they are adapted so as to be preferentially attacked by predators. The nudibranchs might offer packages containing highly repugnant chemicals along with parts of their bodies to the predators, as a defensive variant of the strategic theme of the Trojan horse.Methodology and Principal Findings:We detected, by quantitative 1H-NMR, extremely high local concentrations of secondary metabolites in the MDFs of six species belonging to five chromodorid genera. The compounds were purified by chromatographic methods and subsequently evaluated for their feeding deterrent properties, obtaining dose-response curves. We found that only distasteful compounds are accumulated in the reservoirs at concentrations that far exceed the values corresponding to maximum deterrent activity in the feeding assays. Other basic evidence, both field and experimental, has been acquired to elucidate the kind of damage that the predators can produce on both the nudibranchs' mantles and the MDFs.Significance:As a result of a long evolutionary process that has progressively led to the accumulation of defensive chemical weapons in localized anatomical structures, the extant chromodorid nudibranchs remain in place when molested, retracting respiratory and chemosensory organs, but offering readily accessible parts of their body to predators. When these parts are masticated or wounded by predators, breakage of the MDFs results in the release of distasteful compounds at extremely high concentration in a way that maximizes their repugnant impact. © 2013 Carbone et al