First record ofJaninellanom. nov. (Crustacea: Isopoda: Microparasellidae) in the South Atlantic: revision of the genus and description of a new Brazilian species

Abstract

The family Microparasellidae (Crustacea: Isopoda) is reported for the first time from South America. The genus Janinella nom. nov. is proposed as the replacement name for Paracharon Coineau, 1970. It is new for the Atlantic Ocean. A new species of Janinella from the interstitial Brazilian infralittoral is described. Janinella brasiliensis sp. nov. is distinguished from the New Caledonian congener Janinella renaudae by the tiny antennal scale, the number of teeth of the mandibular incisor and the shape of the maxilliped epipod. These species differ also by the morphology of the male and female pleopods, and the length of the uropodal exopod. Based on the re-examination of J. renaudae and the characters of J. brasiliensis sp. nov., a revised diagnosis of the genus Janinella is provided. Habitat preferences are described: Janinella species live in well-sorted coarse-grained sands affected by high hydrodynamics. The chemical composition of the grains is of low relevance.

A new family Lepidocharontidae with description of Lepidocharon gen. n., from the Great Barrier Reef, Australia, and redefinition of the Microparasellidae (Isopoda, Asellota)

“…Lepidocharon gen. n. shares with Janinella the morphology of the tergites, the first three pereionites with antero-lateral protrusions, the fourth sub-rectangular in shape, and the last three postero-laterally protruded, together with the lateral insertion of pereiopods 1–7 oriented outwards ( vs. ventrally in Janinella , see Albuquerque et al 2014); pereiopodal coxal plates small in Janinella , very reduced and incorporated to body wall in Lepidocharon gen. n. The female operculum of Lepidocharon is more than twice as long as wide, as long as the pleotelson, only faintly incised and bearing 4 apical setae, the mesial pair being close-set. These apical setae resemble that of Janinella species, where only the two close-set setae are present.…”

“…Its monophyletic status had been hypothesised by Coineau and Schmidt (1979) and Coineau (1986, 1994). Since the original diagnosis given by Karaman (1933) (without providing the family name) and the provisional diagnosis given by Wilson and Wägele (1994) in their review of the family Janiridae, it had become clear that several diagnostic characters are weak and others have not been considered in detail (Albuquerque et al 2014), and both the Janiridae and Microparasellidae were placed as incertae sedis ( sedis mutabilis according to Wilson 1987: page 776) in the suborder Asellota.…”

“…15C). Species of Janinella (Albuquerque et al 2014) and Lepidocharon have a shorter and narrower pleonite.…”

“…In general, the exopod is rudimentary in the Janiridae, and in members assigned to the Lepidocharontidae is ovoid and small, as in Microcharon , the most reduced condition being found in Janinella (Albuquerque et al 2014) with a reduced scale, not reaching the tip of the third podomere. Conversely, it is long in Lepidocharon , reaching the fourth podomere, being candle-flame or knife-blade shaped.…”

Microcharon quilli, a new asellote isopod crustacean from interstitial spaces in shallow coralline sands off St. Eustatius, Caribbean Netherlands

“…The marine species are found in shallow sandy bottoms, but no records are known from dredging samples of deeper seafloor sediment. The marine species are further known from intertidal and sandy beaches in the Caribbean, Mediterranean, Brittany (France), English Channel, Galapagos, and New Caledonia (Coineau et al 2013;Albuquerque et al 2014;Galassi et al 2016).…”