Gejavis corsotos, Błażewicz-Paszkowycz & Bamber, 2012

Błażewicz-Paszkowycz, M. & Bamber, R. N., 2012, The Shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae), Memoirs of Museum Victoria 69, pp. 1-235 : 206-210

Gejavis corsotos sp. nov.

Figures 138–140

Material examined. 1 (J58562), holotype, CPBS 03 S, Western Port off Crib Point, 38º21.65'S 145º15.21'E, 2 m depth, sandy-mud, 13 April 1965, Smith-McIntyre grab, coll. A. J. Gilmour ; 1 (J23596), paratype, StnMSL-EG40,EasternBassStrait,11.7 kmW.ofPtRicardo, 37º49.90'S 148º30.01'E, 29 m depth, sand-shell, 28 September 1990, R. V. Sarda, Smith-McIntyre Grab. 1 (J62057) , paratype, Stn. BSS 31 , Eastern Bass Strait, 22 km NNE of North Point, Flinders Island, 39º34.3'S 148º04.0'E, 37 m depth, coarse sand, 26 March 1979, dredge, coll. G.C.B. Poore. 1 (J56376), paratype (dissected), Stn MSL-EG 69, Eastern Bass Strait, 13.3 km E of eastern edge of Lake Tyers, 37º51.7'S 148º14.6'E, 37 m depth, 04 June 1991, coll. N. Coleman , Smith-McIntyre Grab .

Description of female. Body ( Fig. 138A, B) elongate, slender, 2.4 mm long, nine times as long as wide. Cephalothorax subrectangular, tapering from mid-length towards anterior, 1.4 times as long as wide, with slight rounded rostrum, naked; eyes absent. Six free cylindrical pereonites; pereonites 1 to 5 about as long as wide, subequal in length and 0.6 to 0.7 times as long as cephalothorax; pereonite 6 shortest, less than half as long as cephalothorax and 1.3 times as wide as long. All pleonites bearing pleopods, each pleonite with one midlateral seta on each side. Pleotelson rounded, almost three times as long as pleonite 5, 1.3 times as wide as long, with paired distal and laterodistal setae.

Antennule ( Fig. 139A) of four articles, proximal article 1.9 times as long as wide, 0.6 times as long as last three articles together, with mesial and distal outer tufts of penicillate setae and single inner and outer simple distal setae; second article 1.6 times as long as wide, 0.7 times as long as first article, with one outer distal penicillate seta and single inner and outer simple distal setae; third article half length of second with one outer distal penicillate seta and single inner and outer simple distal setae; distal article more slender, 1.6 times as long as third article, with three simple and one penicillate distal setae and single aesthetasc.

Antenna ( Fig. 139B) of six articles, proximal article naked; second article slightly inflated with one small dorsodistal seta; third article half length of second article, with single dorsodistal seta three-times as long as article; fourth article longest, as long as articles 1 to 3 together and 3.5 times as long as wide, with four distal penicillate setae and single simple distal seta exceeding tip of antennule; fifth article 0.4 times as long as fourth, with one distal seta; sixth article 0.25 times as long as fifth, with four distal setae.

Labrum ( Fig. 139C) apically blunt, finely setose. Left mandible not recovered; right mandible ( Fig. 139D) with bilobed pars incisiva, pars molaris basally stout, tapering, with several distal spinules. Labium ( Fig. 139G) with outer distal and subdistal microtrichia. Maxillule ( Fig. 139E) with nine distal spines and outer brush of setules, palp damaged. Maxilla ( Fig. 139F) quadrangular, simple, naked. Maxilliped ( Fig. 139H) endites each with inner-distal rounded tubercle and slightly crenulated distal margin; palp first article with outer distal seta, second and third articles with three inner plumose setae, third article with additional inner simple seta; fourth article with one inner and three distal plumose setae and one outer simple seta; basis naked. Epignath not recovered.

Cheliped ( Fig. 140A) basis with large posterior lobe, wider proximally and extended past anterior margin of pereonite 1 ventrally, about 1.8 times as long as wide; merus subtriangular with one mid-ventral seta; carpus twice as long as wide with paired mid-ventral setae and no shield, proximal and distal single dorsal setae, proximal half of dorsal margin coarsely rugose; propodus longer than wide, with coarse rugosity over outer face and along dorsal margin; inner comb-row of three setae; fixed finger short with lamellate cutting edge, two ventral and three inner setae; dactylus with dorsal margin coarsely rugose, cutting edge naked.

Pereopod 1 ( Fig. 140B) basis damaged in preparation, curved, about 3.5 times as long as wide; ischium compact with single seta; merus just shorter than carpus with single ventrodistal seta and spine; carpus with dorsodistal seta; propodus 1.9 times as long as carpus, with single dorsal and ventral subdistal setae; dactylus half as long as slender unguis, both together 1.4 times as long as propodus. Pereopod 2 ( Fig. 140C) similar to but shorter than pereopod 1; basis 2.5 times as long as wide; merus as long as carpus and with two ventrodistal spines; carpus with one dorsal and two ventral distal spines; unguis 1.7 times as long as dactylus, both together 0.7 times as long as propodus. Pereopod 3 ( Fig. 140D) as pereopod 2, but basis with dorsoproximal penicillate seta.

Pereopod 4 ( Fig. 140E) basis 2.8 times as long as wide; ischium with one ventral seta; merus wider distally, 0.4 times as long as basis, with two ventrodistal spines; carpus 0.9 times as long as merus, with fine dorsodistal spines and three stouter mid- and ventrodistal spines; propodus with one longer dorsodistal and two shorter ventrodistal spines, all shorter than dactylus; dactylus twice as long as unguis, both together 1.4 times as long as propodus. Pereopod 5 ( Fig. 140F) as pereopod 4, but basis broader, 2.4 times as long as wide, and dorsodistal spine on [propodus as long as dactylus. Pereopod 6 ( Fig. 140G) as pereopod 5, but propodus with three dorsodistal spines.

Pleopods ( Fig. 140H) all alike, with naked basis; endopod shorter than exopod and with seven mainly distal plumose setae; exopod with ten distal and outer plumose setae, proximal seta on ventral margin well-separated from remaining setae, most setae about as long as rami.

Uropod ( Fig. 140I) basis naked; exopod of two subequal segments, longer than proximal endopod segment, proximal segment with one distal seta, distal segment with two unequal distal setae; endopod of two subequal segments, proximal segment with one seta, distal segment with one subdistal and four distal simple setae and two distal penicillate setae.

Male. Unknown. Etymology. From the Greek korsotos – “shorn”, referring to the relative lack of spines or setae on pereopod 1 of the present species.

Remarks. See above under Remarks for the genus. Gejavis corsotos sp. nov. was taken from sandy substrata at 2 to 37 m depth, in Western Port and the Eastern Bass Strait.