Pooreotanais gari, Błażewicz-P, 2009

Błażewicz-P, Magdalena, 2009, A new genus of a new Austral family of paratanaoid tanaidacean (Crustacea: Peracarida: Tanaidacea), with two new species., Memoirs of Museum Victoria 66, pp. 5-15 : 7-11

Pooreotanais gari sp. nov.

Figs. 1–3

Material. Holotype female (J56252), stn CPBS 33 S, Western Port , Victoria, 38°22.06'S 145°14.10'E, 13 m depth, on reef with sponge, 5 Mar 1965 . Paratypes and allotype: 2 large females, 2 small specimens (J58851), same locality as holotype; 1 large female (J56254), WBES stn 1747, Western Port , Victoria, 38°27.53'S 145°08.59'E, 18 m depth, sand, 25 Nov 1974 ; 1 large female dissected on slides (J56253); 1 allotype male dissected on slides (J60423), stn CPBS 41 N, Western Port , Victoria, 38°20.81'S 145°13.85'E, 13 m depth, gravel and sand, 30 Mar 1965 .

Description of female. Body (fig. 1B–D) up to 3.5 mm long, glabrous,generally cylindrical, with cephalothorax and pereonites 1 to 3 slender, pereonites 4 and 5 progressively expanding, pereonite 6 and pleon (“abdomen”) grossly inflated; holotype 2.1 mm long, pleon 1.4 mm long. Cephalothorax subrectangular, wider than long, with slight rostrum, eyelobes prominent and eyes absent (fig. 1C–D). Pereonites 1 and 2 shortest, 0.25 times as long as cephalothorax; succeeding pereonites progressively longer, pereonites 3, 4 and 5 respectively 1.4, 2.0 and 3.5 times as long as pereonite 1, pereonite 6 massive, 6.5 times as long as pereonite 1. Pleon of five free subequal pleonites plus pleotelson; each pleonite about 7 times as long as pereonite 1 except pleonite 5 about 5.5 times as long as pereonite 1; pleotelson stout, rounded, 0.7 times as long as last pleonite.

Antennule (fig. 2A) of four articles; proximal article stout, twice as long as wide, 1.2 times as long as distal three articles together, with one simple and five penicillate outer setae in distal half; article 2 just wider than long, 0.3 times as long as article 1, with simple distal outer seta; article 3 about half length of article 2, with simple inner-distal seta; article 4 comparatively slender, 3 times as long as wide and 1.2 times as long as article 2, with three long and one short distal setae and one aesthetasc.

Antenna (fig. 2B) of six articles, proximal article compact, naked; article 2 as long as wide, naked; article 3 as long as wide, with dorsodistal seta; article 4 longest, more than twice as long as article 3, 2.6 times as long as wide, with two inner penicillate setae and two simple distal setae; article 5 0.35 times as long as article 4 with one distal seta; article 6 comparatively minute, one-third length of article 5, with one subdistal and three distal strong setae.

Labrum (fig. 2C) rounded, naked. Left mandible (figs. 2D, D’) with eleven elongate teeth distally on pars incisiva; lacinia mobilis a slight, fused tooth; pars molaris a short spike without rugosity; right mandible (figs. 2E, E’) with nine distal elongate teeth, without lacinia mobilis. Labium (not figured) naked, without palp. Maxillule (fig. 2F) with six distal and two subdistal spines, and sparse microtrichia on inner distal face; palp distinct, unsegmented, with two distal setae. Maxilla (not figured) small, ovoid, naked. Maxilliped (figs. 2G, G’) palp article 1 wide, naked; article 2 almost triangular, no outer setae, two simple inner setae, distal-most inner seta exceeding distal margin of palp article 3; article 3 as wide as long, with no inner or outer setae, sparse inner submarginal microtrichia; article 4 with single subdistal simple seta and four distal setae minutely denticulate in their distal half; basis naked; endites large, naked. Epignath (fig. 2H) elongate, tapering from bilobed anterior, naked.

Cheliped (figs. 3A, A’) robust, with rounded, elongate basis about twice as long as wide; merus subtriangular with one ventral seta; carpus just longer than wide, with fine mid-dorsal seta, longer dorsodistal seta, but no ventral setae; propodus longer than wide, with one ventral seta, cutting-edge of fixed finger almost perpendicular to axis of propodus, fixed finger with one proximal and three distal outer setae, cutting edge minutely crenulated distally, inner setal row at base of dactylus of three setae; dactylus with proximal outer seta only.

Pereopod 1 (fig. 3B) coxa naked; basis slender, 5.2 times as long as wide, naked; ischium compact, naked; merus shorter than carpus, naked; carpus with one dorsal subdistal seta; propodus almost as long as carpus and merus together, with single ventral subdistal seta; dactylus slender with dorsoproximal setal tuft, extending into longer slender unguis, the two together some 0.75 times as long as propodus. Pereopod 2 (fig. 3C) similar to pereopod 1, but propodus with two subdistal setae. Pereopod 3 (fig. 3D) similar to pereopod 2, but basis with penicillate seta, dactylus with one longer seta in proximal setal tuft.

Pereopods 4 and 5 (fig. 3E) identical to each other, basis stouter than on anterior pereopods, 3.9 times as long as wide, naked; ischium with one ventrodistal seta; merus and carpus subequal, merus with two minutely denticulate, subdistally bifurcate ventrodistal spines; carpus with fine outer distal seta and two minutely denticulate, subdistally bifurcate ventrodistal spines; propodus with three minutely denticulate ventrodistal spines and adjacent simple seta; dactylus and unguis not fused, unguis shorter than dactylus, distally bifurcate. Pereopod 6 (fig. 3F) as pereopod 5, but propodus bearing distal marginal microtrichia and only two minutely denticulate ventrodistal spines.

Pleopods absent.

Uropod as in male.

Description of male. Similar in appearance to but smaller than female (fig. 1A) (allotype length 1.72 mm), pleon 0.55 times total body length; cephalothorax 4 times as long as each of subequal pereonites 1 to 3, pereonite 4 expanded, twice as long as pereonite 1, pereonite 5 three times as long as pereonite 1, pereonite 6 just shorter than pereonite 5. Inflated pleonites each bearing pair of pleopods.

Antennule, antenna, mouth part, cheliped and pereopods the same as in female.

Pleopods (fig. 3H) biramous; exopod twice as long as wide with nine setae distally; endopod little shorter than exopod with one inner seta and 6 setae distally. All setae simple.

Uropod (fig. 3G) compact, biramous, basis wide and naked; exopod of one segment, half as long as proximal endopod segment, with one shorter and one longer distal setae; endopod of two segments, proximal segment as wide as long, naked, distal segment little shorter than proximal segment, with three distal setae.

Etymology. Named in honour of Gary Poore (noun in apposition), in gratitude for all his assistance to both authors over many years—and for originally introducing us.