Gynodiastylis bacescui, Petrescu, Iorgu & Chatterjee, Tapas, 2011

Petrescu, Iorgu & Chatterjee, Tapas, 2011, New species and new records of cumaceans (Crustacea: Peracarida: Cumacea) from the Andaman Islands, Indian Ocean, Zootaxa 2966, pp. 51-57 : 55-56

publication ID	https://doi.org/ 10.5281/zenodo.201857
DOI	https://doi.org/10.5281/zenodo.6185826
persistent identifier	https://treatment.plazi.org/id/AF4FC330-FFAD-FF9B-03DF-2A9A1F07FE57
treatment provided by	Plazi
scientific name	Gynodiastylis bacescui
status	sp. nov.

Treatment

G ynodiastylis bacescui sp. nov.

( Fig. 2 View FIGURE 2 A–J)

Material examined. Holotype manca ( MGAB CUM 1689). South Andaman: Wandoor (11°40.55’N, 92°45.12’E), Port Blair, Andaman Islands, intertidal sediments among macroalgae ( Padina sp.), December 2005; coll. T. Chatterjee.

Diagnosis. Elongated carapace, rounded and large telson, reaching half of uropodal peduncle, basis of maxilliped 3 with one short outer plumose seta, uropodal endopod with three articles.

Description. Manca. Body, 3.39 mm in length.

Carapace ( Fig. 2 View FIGURE 2 B). 0.42 of entire body length, 1.7 longer than high, pseudorostral lobes about 0.34 of frontal lobe, ocular lobe, large, rounded, without any visual elements, distinct antennal notch, slight serrate ventral margin.

Pereon. 0.14 of entire body length, first segment hardly visible dorsally.

Pleon. 0.5 of entire body length, segments robust.

Antenna 1 ( Fig. 2 View FIGURE 2 C, D). Short, basal article of peduncle as long as other two articles together, main flagellum with three articles and aesthetascs, accessory flagellum with two articles and one apical sensory seta.

Maxilliped 3 ( Fig. 2 View FIGURE 2 E). Basis 0.45 times as long as entire maxilliped length, two plumose setae on medial margin, without outer process, ischium with one short plumose seta, merus with one long plumose seta on outer margin, carpus as long as ischium and merus together, with one short plumose seta on outer margin, propodus 1.13 times as long as carpus, two short pappose setae on medial margin, dactylus 1.24 times as long as propodus, with short hairs on medial margin. Exopod, small, with three-articled flagellum.

Pereopod 1 ( Fig. 2 View FIGURE 2 F). Large basis with serrate medial margin, 3 pappose apical setae, rest of pereopod broken. Exopod 2.25 times as long as exopod of maxilliped 3.

Pereopod 2 ( Fig. 2 View FIGURE 2 G). Basis 0.32 of entire pereopod length, twice as long as merus, as long as propodus and dactylus together, dactylus 1.15 times as long as propodus. Exopod fully developed.

Pereopod 3 ( Fig. 2 View FIGURE 2 H). Large articles, basis 0.43 times as long as entire pereopod length, 1.5 times as long as merus, merus second largest article, 2.2 times as long as ischium, 2.7 times as long as carpus, 1.12 times as long as propodus, propodus 1.14 times as long as dactylus, dactylus with short terminal robust curved seta like a claw.

Pereopod 4 ( Fig. 2 View FIGURE 2 I). Large articles, basis 0.39 times as long as entire pereopod length, merus 2 times as long as ischium, 2.7 times as long as carpus, 1.5 times as long as propodus, propodus 0.8 times as long as dactylus, dactylus with short terminal robust curved seta like a claw.

Uropod ( Fig. 2 View FIGURE 2 J). Peduncle as long as last pleonite, with strongly serrate medial margin, 1.19 times as long as endopod, exopod 0.6 times as long as endopod, with two articles, one robust curved terminal seta, endopod with three articles, proximal article 1.5 times as long as median article, with robust curved terminal seta. Telson round and large, 0.66 times as wide as last pleonite, 0.52 times as long as uropodal peduncle.

Male. Unknown.

Etymology. The species is named in honour of Mihai Bäcescu (1908–1999), famous Romanian specialist in Cumacea , and master of the first author (IP).

Remarks. G ynodiastylis bacescui sp. nov. resembles G. carinirostris Hale (1946) and G. hartmeyeri Zimmer (1914) , both of them recorded from New South Wales, Bass Strait ( Australia), in having a carapace much longer than high and a uropodal endopod with three articles. It differs from G. carinirostris by lacking visual elements and from G. hartmeyeri by having a more rounded telson. Such a round telson can also be found in G. fulgida Day (1980) and G. profunda Day (1980) , both from South Africa and with a uropodal endopod with one article and in G. blax Gerken (2001) from South Australia (with a shorter telson than the new species from Andaman and a uropodal endopod with two articles). G. bacescui sp. nov. differs from all of these species in having the basis of maxilliped 3 with a short plumose outer seta (in contrast with three or four outer setae in the other above-mentioned species) and especially by its enlarged merus of pereopod 3. This is the first record of the genus Gynodiastylis from India.