The Shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae) Author Błażewicz-Paszkowycz, M. Author Bamber, R. N. text Memoirs of Museum Victoria 2012 69 1 235 journal article 1447-2554 F060EED2-88C1-4A9A-92A7-6C06905F307B Bathytanais bathybrotes (Beddard, 1886) Figures 65–67 Paratanais bathybrotes Beddard, 1886 (a), 119 – Bathytanais bathybrotes Bamber, 2008 , 175–176, literature. Material examined. 12 specimens (including 2 brooding) (J56271), 1 (J56272), from sand wall at front of Pope’s Eye , Port Philip Bay , 7 m depth , 28 February 1982 , coll. R Lipson . The female of this species was comprehensively redescribed by Lang (1972) ; however, the male was previously unknown – indeed, no male of any Bathytanais species has been recorded before, making the following description particularly important. Description of male . Body ( Fig. 65A, B ) with typical gross appearance of a Paratanais male, 2.1 mm long, 5.3 times as long as wide. Cephalothorax subrectangular, as long as wide, as long as pereonites 1 to 3 together, with conspicuous subtriangular rostrum; eyes large, one-third as long as cephalothorax, with black ommatidia. Pereonite 1 shortest, pereonites 2, and 3 subequal in length, 1.4 times as long as pereonite 1, pereonites 4 and 5 subequal, 1.8 times as long as pereonite 1, pereonite 6 just shorter than pereonite 5 (all pereonites respectively 3.6, 2.7, 2.8, 2, 2 and 2.3 times as wide as long). Pleon of five free subequal pleonites bearing pleopods, ventrally with blunt keel; pleonites 2.7 times as wide as long and 1.2 times as long as pereonite 1. Pleotelson ( Fig. 47K ) semicircular, as long as pereonite 6, 1.5 times as wide as long. Antennule ( Fig. 66A ) of three peduncular and four flagellar articles, proximal peduncle article 1.9 times as long as wide, with outer mesial tufts of penicillate setae, inner distal simple seta; second article just shorter than wide, 0.4 times as long as first article, with outer-distal tuft of penicillate setae; third article one-third length of second, with two simple distal setae; first flagellar article half as long as third peduncle article, with proximal and distal rows of six or seven aesthetascs and outer-distal simple seta; second and third flagellar articles subequal in length, four times as long as first, with distal rows of six aesthetascs; fourth flagellar article just shorter than third, distally with four simple setae, one penicillate seta and one aesthetasc. Antenna ( Fig. 66B ) of six articles, proximal article compact, naked; second article with ventrodistal tuft of three penicillate setae and one ventrodistal and one dorsodistal simple setae; third article as long as wide, 0.6 times as long as second article, with dorsodistal seta; fourth article twice as long as third, with one mid-dorsal and three dorsodistal penicillate setae, single dorsal and ventral subdistal simple setae; fifth article 0.9 times as long as fourth with one dorsal subdistal seta; sixth article minute with five simple and one penicillate distal setae. Mouth parts underdeveloped in comparison with those of female. Labrum ( Fig. 66C ) apically rounded, naked. Mandibles absent. Maxillule ( Fig. 66D ) with naked endite and simple palp bearing distal setule; maxilla ( Fig. 66D ) ovoid, naked. Maxilliped ( Fig. 66E ) endites relatively wide, with two minute ovate tubercles and single inner seta; palp first article with outer-distal seta; second article with three inner-distal simple setae; third article with three inner setae in proximal half; fourth article with five inner to distal setae and one outer subdistal seta; single inner seta on basis not reaching distal margin of endites. Cheliped ( Fig. 66F ) compact, basis twice as long as wide, naked; merus subtriangular, ventrally convex, with one mid-ventral seta; carpus 1.3 times as long as wide with two mid-ventral setae, one dorsoproximal and one dorsodistal fine setae; propodus as long as wide, with inner comb-row of 12 setae; fixed finger just shorter than palm, with two ventral setae, three setae adjacent to cutting edge; dactylus with dorsoproximal seta, two proximal setae on cutting edge. Fig. 65. Bathytanais bathybrotes , male. A, lateral; B, dorsal. Scale = 0.2 mm. Fig. 66. Bathytanais bathybrotes , male.A, antennule; B, antenna; C, labrum; D, maxillule and maxilla; E, maxilliped; F, cheliped. Scale = 0.1 mm. Fig. 67. Bathytanais bathybrotes , male. A, pereopod 1; B, pereopod 2; C, pereopod 3; D, pereopod 4; E, pereopod 5; F, pereopod 6; G, pleopod; H, uropod. Scale = 0.1 mm. Pereopod 1 ( Fig. 67A ) longer than others, coxa simple with seta; basis slender, 4.25 times as long as wide with dorsoproximal penicillate seta; ischium compact with single seta; merus one-third as long as basis, with fine ventrodistal seta; carpus 0.9 times as long as merus, with fine ventrodistal seta and two dorsodistal setae; propodus 1.8 times as long as carpus, with one dorsal and two ventral subdistal setae, and dorsal and ventral marginal microtrichia; dactylus half as long as slender unguis and with distal seta, dactylus and unguis together 0.9 times as long as propodus. Pereopod 2 ( Fig. 67B ) similar to pereopod 1, but more compact, basis 3.4 times as long as wide; merus and carpus equal in length, carpus without dorsodistal setae; propodus with two dorsal and one ventral subdistal setae, dactylus with proximal seta. Pereopod 3 ( Fig. 67C ) similar to pereopod 2. Pereopod 4 ( Fig. 67D ) basis stout, 2.6 times as long as wide, with three ventral subdistal penicillate setae; ischium with two ventral setae; merus one-third as long as basis, naked; carpus as long as merus, with two ventrodistal and one dorsodistal tooth-like spines; propodus 1.7 times as long as carpus with dorsodistal seta, two ventrodistal spines, mid-distal penicillate seta and marginal rows of penicillate setae; dactylus long and slender, four times as long as distinct unguis, both together 0.8 times as long as propodus. Pereopod 5 ( Fig. 67E ) similar to pereopod 4, but basis with dorsoproximal pair of penicillate setae, merus with two ventrodistal tooth-like spines, carpus with additional larger outer distal spine and dorsodistal seta, dactylus and unguis distinctly more curved. Pereopod 6 ( Fig. 67F ) as pereopod 5. Pleopods ( Fig. 67G ) all alike, with naked basis, rami subequal; endopod with inner subdistal plumose seta and 13 plumose setae around outer margin; exopod without setae on inner margin, 19 plumose setae around outer margin. Uropod ( Fig. 67H ) basis naked; exopod of two subequal segments, together more than half as long as endopod, first segment with simple outer-distal seta, second segment with two unequal distal simple setae; endopod of three segments, proximal segment short, naked, second segment twice as long as first, with proximal array of seven penicillate setae, distally with one simple and one penicillate setae; third segment as long as second, distally with five simple and one penicillate setae. Remarks . The history of this species was discussed by Bamber (2008) , from which we may disregard the type-locality as being a lapsus calami . Bathytanais bathybrotes was previously known from New South Wales at depths of 6 to 50 m depth ( Beddard, 1886b ; Lang, 1972 ) and from Moreton Bay, Queensland at depths between 8 and 42 m ( Bamber, 2008 ) on clean sand. The present material extends its distribution further west to Victoria . The Bathytanais male is very similar to males of Paratanais species , and does not show the expanded antenna peduncle articles of the females, but appears to differ in the presence of a proximal seta on the dactyli of pereopods 2 and 3. Discovery of the males of other species is necessary to confirm this as a generic character.