Ozagathus watharongus, 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 : 201-206

Ozagathus watharongus sp. nov.

Figures 135–137

Material examined. 1 (J58854), holotype, MSL EG120, Eastern Bass Strait , 11.7 km W of Pt Ricardo, 37º49.54'S 148º30.01'E, 29 m depth, 28 September 1990, coll. Marine Science Laboratories. 1 (J56381), paratype, MSL-EG 68, Eastern Bass Strait , 13.3 km E of eastern edge of Lake Tyers, 37º51.42'S 148º14.36'E, 121 m depth, 04 June 1991, coll. N. Coleman ; 1 (J23653), paratype, MSL-EG 41, Eastern Bass Strait , 11.7 km W of Pt Ricardo, 37º49.54'S 148º30.01'E, 29 m depth, sand and shell, 28 September 1990, Smith-McIntyre Grab, coll. Marine Science Laboratories. 1 (J50793), paratype, VC 48 C1, Eastern Bass Strait , 37º21.43'S 149º29.57'E, 40 m depth, 09 May 1998, coll. N. Coleman , Smith-McIntyre Grab. 1 (J28426) , paratype, MSL-EG 121, Eastern Bass Strait , 11.7 km W of Pt Ricardo, 37º49.54'S 148º30.01'E, 29 m depth, sand and shell, 28 September 1990, Smith-McIntyre Grab, coll. Marine Science Laboratories. 17 (J28413), paratypes, MSL-EG 86, EasternBassStrait,2.9 kmSEofCapeConran, 37º50.00'S 148º38.54'E, 95 m depth, coarse sand, 04 June 1991, Smith-McIntyre grab, coll. N. Coleman. 30 (J28416), paratypes, MSL-EG 90, Eastern Bass Strait , 7.3 km SSW of Cape Conran, 37º52.39'S 148º42.09'E, 161 m depth, coarse sand, 04 June 1991, Smith-McIntyre grab, coll. N. Coleman. 2

(J50792), paratypes, Stn VC 37 C1, Eastern Bass Strait, 38º18.3'S 147º15.25'E, 40 m depth, 10 May 1999, Smith-McIntyre grab, coll. N. Coleman. 19 (J28420), paratypes, MSL-EG 114, Eastern Bass Strait , 2.9 km SE of Cape Conran, 37º50.00'S 148º38.54'E, 29 m depth,coarse sand, February 1991, Smith-McIntyre grab, coll. N. Coleman. 4 (J23525), paratypes, MSL-EG 45, Eastern Bass Strait , 13.3 km E of eastern edge of Lake Tyers, 37º51.44'S 148º14.46'E, 37 m depth, sand and shell, 25 September 1990, Smith-McIntyre grab, coll. Marine Science Laboratories. 22 (J23532), paratypes, MSL-EG 59, Eastern Bass Strait , 9.5 km SW of Cape Conran, 37º52.53'S 148º39.29'E, 48 m depth, sand and shell, 28 September 1990, Smith-McIntyre grab, coll. Marine Science Laboratories.

Description of female. Body ( Fig. 135A, B) slender, holotype 1.9 mm long, 8.7 times as long as wide. Cephalothorax subrectangular, tapering in anterior third with slight triangular rostrum, 1.6 times as long as wide, almost as long as pereonites 1 and 2 together, wider than pereon, naked; eyelobes and eyes absent. Pereonites almost barrel-shaped, pereonite 1 widest anteriorly, pereonites 2 to 5 centrally, pereonite 6 posteriorly; pereonites 1 and 5 subequal in length, half as long as cephalothorax; pereonites 2 and 4 just longer than pereonite 1; pereonite 3 longest, 1.3 times as long as pereonite 1; pereonite 6 shortest, 0.8 times as long as pereonite 1 (all pereonites respectively 1.2, 1.0, 0.9, 1.0, 1.1 and 1.3 times as wide as long). Pleon just narrower than pereon, pleonites without pleopods, each 4.5 times as wide as long; pleonite 5 with conspicuous midlateral seta on each side. Pleotelson subpentangular, 0.4 times length of pleon and as wide as long.

Antennule ( Fig. 136A) of three articles, proximal article 4.2 times as long as wide, 1.35 times as long as distal two articles together, outer margin with mid-length and distal tufts of four penicillate and one simple setae, mid-length seta exceeding tip of proximal article, distal seta exceeding tip of antennule; second article as long as wide, 0.2 times as long as first article, with simple outer distal seta; third article 1.2 times as long as second article, with five simple and one penicillate distal setae.

Antenna ( Fig. 136B) of five apparent articles, proximal article totally fused to carapace; second article as long as wide, naked; third article just longer than wide, as long as second article, with fine dorsodistal seta; fourth article longest, 2.2 times as long as second article and nearly four times as long as wide, with subdistal ventral penicillate seta; fifth article one-third as long as fourth, naked; sixth article half as long as fifth, distally with three simple and one penicillate setae.

Labrum ( Fig. 136E), compact, rounded, distally setulose. Left mandible ( Fig. 136F) with three rounded lobe-like “teeth” on pars incisiva, lacinia mobilis reduced to a similar rounded subdistal tubercle, pars molaris flaccid, blunt, directed proximally. Labium ( Fig. 136H) with prominent setose, rounded mediodistal processes. Maxillule ( Fig. 136G) with eight distal spines and sparse groups of microtrichia, palp ( Fig. 136 G') with two distal setae. Maxilla not recovered. Maxilliped ( Fig. 136I) palp first article naked, second article with two inner distal setae; third article with two inner setae in distal half; fourth article tapering, with five setae along inner margin to tip, single outer subdistal seta; all palp setae other than the last distally finely denticulate; bases fused, naked; endites distally with rudiment of outer rounded tubercle. Epignath ( Fig. 136J) elongate, distally pointed, naked.

Cheliped ( Fig. 137A) basis compact, 0.85 times as long as wide, naked; merus subtriangular, outer face with strip of six rounded tubercles and single seta along dorsodistal margin; carpus 1.6 times as long as wide, with two unequal midventral setae, one fine dorsodistal seta and one fine mid-dorsal seta, and strip of five rounded tubercles along ventral margin of outer face; propodus longer than wide with ventral submarginal strip of six rounded tubercles and group of smaller tubercles dorsodistally, fixed finger 0.8 times as long as palm, with one ventral seta, three setae adjacent to cutting edge, small “teeth” centrally and distally on cutting edge; dactylus with rounded tubercles along dorsal margin and proximally on inner face, two blunt tubercles on cutting edge.

Pereopod 1 ( Fig. 137B) coxa with seta; basis slightly arcuate, slender, five times as long as wide, naked; ischium compact, with ventral seta; merus 0.3 times as long as basis, ventrodistally with two setae; carpus 1.3 times as long as merus, distally with one dorsal, and one shorter and one longer ventral finely-denticulate spines; propodus 1.5 times as long as carpus, ventrally with subdistal spine and seta; dactylus short and robust, tapering unguis 1.7 times as long as dactylus, both together 0.7 times as long as propodus.Pereopod 2 ( Fig. 137C) similar to but somewhat stouter than pereopod 1, basis 3.7 times as long as wide, propodus without subdistal seta but with dorsodistal spine-like apophysis. Pereopod 3 ( Fig. 137D), similar to pereopod 2.

Pereopod 4 ( Fig. 137E) basis 4.2 times as long as wide; ischium with two ventrodistal setae; merus 0.4 times as long as basis, with two finely-denticulate ventrodistal spines; carpus as long as merus, distally with outer and inner finely-denticulate spines and fine dorsal seta; propodus 1.3 times as long as carpus, distally with three finely-denticulate spines and dorsodistal spine-like apophysis; dactylus about half as long as curved unguis, unguis slender, finely denticulate, both together 1.3 times as long as propodus. Pereopod 5 ( Fig. 137F) as pereopod 4, but basis with two penicillate setae. Pereopod 6 ( Fig. 137G) as pereopod 4, but basis naked.

Pleopods absent.

Uropods ( Fig. 137I) held ventrally beneath pleotelson; basis naked but with slight fused exopod with two distal setae exceeding tip of endopod and visually conspicuous in dorsal view of animal ( Fig. 135); endopod of one segment, widest proximally, with one simple and two penicillate setae in proximal half, three simple and two penicillate setae distally.

Distinctions of male. Of similar overall appearance to female; antennule ( Fig. 136C) stouter, proximal two articles respectively 3.5 and 0.7 times as long as wide; antenna ( Fig. 136D) also slightly stouter, second and third articles shorter than wide, fourth article three times as long as wide; pleopods present ( Fig. 137H), somewhat rudimentary, biramous, rami with incomplete articulation with naked basis, each with distal tuft of fine setules.

Etymology. The Wathaurong were another of the indigenous hunter-gatherer tribes of the Melbourne region in the mid-nineteenth century (see under Paragathotanais wurundjeri above) (noun in apposition).

Remarks. See above under Remarks for the genus. Ozagathus watharongus sp. nov. was collected frequently in the Eastern Bass Strait, at depths from 29 to 161 m on coarse or shelly sands.