A new species in the genus Acartia Dana, 1846 (Crustacea, Copepoda, Calanoida, Acartiidae) from the South Pacific coastal waters of Nadi Bay, Fiji

A new species in the genus Acartia, Acartia nadiensissp. nov., is described from Fijian coastal waters. This species belongs to the subgenus Odontacartia based on the following morphological features: presence of a rostral filaments, a pointed process on the last prosomite, a serrated terminal spine on female P5, and the absence of a protrusion on the basis of the male right P5. This new species can be differentiated from its congeners by the combination of the absence of a spine on the first segment of the antennules, the short outer seta of female P5, and a medial spine on the exp-2 of the left male P5. Phylogenetic analyses using mitochondrial COI partial sequences show that the new species is distinct from its congeners.

Rediagnosis of the squat lobster genus Gastroptychus Caullery, 1896, with a new genus Sternostylus and a new family Sternostylidae (Crustacea: Decapoda: Anomura: Chirostyloidea)

The chirostyloidean squat lobster genus Gastroptychus Caullery, 1896 is revised and is split into two genera: Gastroptychus sensu stricto (type species, Ptychogaster spinifer A. Milne-Edwards, 1880) and Sternostylus new genus (type species, Ptychogaster formosus Filhol, 1884). Gastroptychus sensu stricto, is restricted to nine species with a sternal plastron, at sternite 3, abruptly demarcated from the preceding sternites (excavated sternum) by a distinct step forming a well-defined transverse or concave anterior margin at the articulation with maxillipeds 3, the maxillipeds 3 widely separated, with the distal parts accommodated in the excavated sternum between the left and right maxillipeds 3 when folded, and the P2–4 dactyli with the terminal spine demarcated by a suture. Sternostylus new genus, represented by 12 species, has the sternite 3 anteriorly bluntly produced medially and steeply sloping anterodorsally to the anterior sternite, with a pair of spines directly behind the anterior margin, the left and right maxillipeds 3 adjacent, and the P2–4 dactyli ending in an indistinctly demarcated corneous spine. The above-mentioned characters of Gastroptychus are consistent with Chirostylidae sensu stricto. Published molecular phylogenies indicate, however, that Sternostylus is the sister group to all the other Chirostylidae, and is designated the type genus of a new family, Sternostylidae.

Onset of Maturity and Ontogenetic Tagmatization of the Pygidium in the Development of Lonchopygella megaspina (Trilobita, Later Furongian, Cambrian)

Onset of maturity in trilobites is generally considered to occur when the last trunk segment is released into the thorax, marking the start of the holaspid stage. Here we describe striking morphological changes that occur within the holaspid ontogeny of Lonchopygella megaspina Zhou in Zhou et al., 1977, which include the effacement of dorsal furrows, the rapid and complete degeneration of pygidial lateral spines, and the increasing prominence of a pygidial axial spine. These notable changes, which are not coincident with the onset of the holaspid phase, emphasize that the onset of maturity in trilobites should be viewed on a character-by-character basis before assessing whether the exoskeleton as a whole can be described as mature. The holaspid pygidial condition in L. megaspina may represent an intermediate step in an evolutionary transition in the number, form, and allocation of segments in the tsinaniid trunk. Pygidial transition from a dynamically changing complement of segments in the meraspid phase to a static complement in the holaspid phase was accompanied by a marked change in the extent to which segment boundaries defined pygidial structure. Attaining this static complement allowed subsequent pygidial development to emphasize its structure as an integrated unit in which internal segmental boundaries became diffuse, a continuous margin to become prominent, and an elongated terminal spine, first evident at onset of epimorphic growth, to develop allometrically. Trilobite body development suggests that while the segmented construction placed constraints on how morphology varied, the influence of these constraints diminished following completion of thoracic segment construction. Selective premium for a distinct posterior tagma might favor the early ontogenetic acquisition of such a structure, and could have been a driver of the repeated trend toward caudalization witnessed among derived trilobite clades.

Caridina vithuraensis sp. nov. (Decapoda: Atyidae) from Vamanapuram River, Kerala region of Western Ghats, India

A new species of Caridina H. M. Edwards, 1837, namely, C. vithuraensis, collected from Kallar, a tributary of Va-manapuram River, Kerala at Vithura is being described in this paper. The species is characterized by : small shrimps hav-ing short rostrum, extending to the tip of 1st segment of antennular peduncle, rarely reaching beyond, rostral formula : 11–19/2–5 (2–5 post-orbital); carpus of 1st pereiopod deeply excavated, 1.3 to 1.45 times as long as broad; dactylus of 3rdpereiopod ends in a terminal spine and with 5–7 accessory spines; dactylus of 5th pereiopod with 24–45 comb-likespinules; appendix interna on endopod of male 1st pleopod is prominent; uropodal diaeresis with 16–20 spines; telson con-ical in shape with 4–6 pairs of spinules on the dorsal and 6–8 spinules at the distal end. The species shows affinities withspecies like C. malayensis Cai et al., 2007; C. congoensis Richard & Clark, 2009 and C. roubaudi Richard & Clark, 2009. However they can be separated based on the specific characters given in Table 1.

New species of Paracalanidae along the west coast of India: Paracalanus arabiensis

A new species of copepod, Paracalanus arabiensis sp. nov. collected from Mandovi and Zuari estuaries, Goa, central west coast of India, is described. It differs from its congeners mainly in the structure of leg 5, with a row of six teeth along the edge of inner terminal spine resulting in a serrated margin and two small, stiff spines of equal length protrude in between the terminal spines.

Five new species of chirostylid crustaceans (Crustacea: Decapoda: Anomura: Chirostylidae) from Taiwan

Five new species of chirostylid crustaceans from Taiwan are described. Eumunida chani sp. nov. is characterized by the absence of a pad of densely-packed setae on the pereopod 1, the anterior branchial margin bearing two spines, and the carpus of first pereopod with only two spines. Uroptychus anacaena sp. nov. and U. anatonus sp. nov. are similar but separated from each other by the shape of sternite 4 and relative length of the antennal scale. These species closely resemble U. maori Borradaile, 1916 and U. brucei Baba, 1986, but lack a ventral subterminal spine on the ischium of pereopod 1. Uroptychus orientalis sp. nov. is separated from U. occidentalis Faxon, 1893 by the shorter antennal scale and P2–4 dactyli with ultimate and penultimate spines subequal in size. Uroptychus singularis sp. nov. is distinguished from U. australis (Henderson, 1885) by the single, unpaired terminal spine on the flexor margin of pereopods 2–4.

Acanthocopinae (Crustacea: Isopoda: Munnopsididae) from the Southern Ocean deep sea with the description of Acanthocope eleganta sp. nov.

Acanthocope eleganta sp. nov. is described from the abyssal Southern Ocean near the Southern Ocean Peninsula. The new species differs from others in the following: a slender dorsomedial spine on the pleon anteriorly, a pair of short dorsal spines and long ventral spine on each of pereonites 5 and 6; uropods half as long as the terminal spine of the pleotelson and with a minute exopod. A. annulatus Menzies, 1962 is redescribed; A. galatheae Wolff, 1962, previously known only from the Gulf of Panama and from Angola Basin, is recorded from the northwest Weddell Sea.

Anatolepis from the Early Ordovician of East Greenland - not a fishy tail

Fragments from the Cape Weber Formation (Early Ordovician) of East Greenland assigned to the supposed vertebrate Anatolepis are iIIustrated. The presence of a well preserved terminal spine suggests arthropod rather than vertebrate affinities.