Paratanais tanyherpes, 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 : 91-95

Paratanais tanyherpes sp. nov.

Figures 60–62

Material examined. 1 (J56762), holotype, Stn CPBS-N 32 , Western Port, off Crib Point, 30º20.83'S 145º13.48'E, 13 m depth, sandy gravel, 23 March 1965, coll. A.J. Gilmour , Smith-McIntyre Grab. 1 (J56763) , paratype, Stn CPBS-A 4 , Western Port, off Crib Point, 38º21'S 145º14'E, 9 m depth, sand, 12 October 1964, coll. A.J. Gilmour , Smith-McIntyre Grab. 4 (J56755) , paratypes, Stn CPBS-N 31 , Western Port, off Crib Point, 38º20.93'S 145º13.62'E, 15 m depth, fine sand and mud, 29 March 1965, coll. A.J. Gilmour , Smith-McIntyre Grab. 1 (J56757) , paratype, Stn CPA 22 , Cape Paterson, Victoria, 38º41'S 145º36'E, 0 m depth, 07 March 1982, coll. R. S. Wilson & H.M. Lew- Ton. 2 (J56754) , paratypes, Stn BSS 174 S, Eastern Bass Strait, 25 km NE of Deal Island, Tasmania, 39º16.8'S 147º33.2'E, 57 m depth, medium sand, 18 November 1981, coll. R. S. Wilson, WHOI epibenthic sled. 2 (J56761) , paratypes, Stn BSS 155 , Central Bass Strait, 38 km SW of Cape Paterson, 38º55.5'S 147º17.0'E, 70 m depth, fine sand, 12 October 1964, coll. R. S. Wilson. 1 (J57533) , paratype, Stn BSS 203 , Central Bass Strait, 44 km NE of Cape Wickham, King Island, 39º22'S 144º18.3'E, 60 m depth, coarse sand, 23 November 1981, coll. R. S. Wilson. 1 (J56689) , paratype, Stn BSS 199 , Western Bass Strait, 20 km SSW of Stokes Point, King Island, 40º19.5'S 143º48.8'E, 71 m depth, fine mud, 22 November 1981, coll. R. S. Wilson. 3 (J56722) , paratypes, Stn BSS 192 DRC, Western Bass Strait, 44 km SW of Cape Otway, 39º06.7'S 143º07.4'E, 81 m depth, medium sand, 21 November 1981, coll. R. S. Wilson. 4 (J56705) , paratypes, Stn BSS 209 , Eastern Bass Strait, 40 km SSW of Lakes Entrance, 38º18.0'S 147º37.0'E, 55 m depth, muddy fine shell, 31 July 1983, coll. M.F. Gomon & R.S. Wilson. 3 (J56764) , paratypes, Stn BSS 173 , Eastern Bass Strait, 30 km north of North Point Flinders Island, 39º26.3'S 147º48.7'E, 49 m depth, medium sand, 17 November 1981, coll. R. S. Wilson. 1 (J56756) , paratype, Stn CPBS-S 32 , Western Port, off Crib Point, 38º21.6'S 145º13.7'E, 13 m depth, muddy sand, 12 March 1965, coll. A.J. Gilmour. 1 (J56765), 2 (J56758), 1 (J56759), paratypes, Stn CPBS-N 32 , Western Port, off Crib Point, 38º20.83'S 145º13.48'E, 13 m depth, sandy gravel, 23 March 1965, coll. A.J. Gilmour , Smith-McIntyre Grab. 1 (J57542) , paratype, Stn CPBS-S 26 , Western Port, off Crib Point, 38º22.18'S 145º15.22'E, 10 m depth, sand, 26 February 1965, coll. A.J. Gilmour , Smith-McIntyre Grab. 1 (J57563) , paratype, Stn SPPS 5 , Southern Port Phillip Bay, 38º17.3'S 144º41.4'E to 38º16.4'S 144º41.8'E, 7 m depth, coll. Marine Research Group of Victoria, dredge.

Description of female. Body ( Fig. 60A) elongate, 8.7 times as long as wide, holotype 3 mm long.Cephalothorax subrectangular, 1.4 times as long as wide, twice as long as pereonite 1, with slight triangular rostrum, naked. Pereonite 1 shortest, pereonites 2 and 3 about 1.5 times as long as pereonite 1; pereonite 4 longest, 1.9 times as long as pereonite 1; pereonites 5 just shorter than pereonite 4, pereonite 6 just shorter than pereonite 2 (all pereonites respectively 1.5, 1.1, 1.0, 0.9, 0.9 and 1.1 times as wide as long). Pleonites 3.6 times as wide as long, pleonites 1 to 4 with one plumose, articulating lateral seta on each side. Pleotelson semicircular, short, twice as long as pleonite 5, 1.7 times as wide as long, distally with four posterolateral setae, marginal single simple setae either side of each uropod attachment, and marginal penicillate seta distal of uropod attachment ( Fig. 62I).

Antennule ( Fig. 61A) of five articles, shorter than cephalothorax; proximal article 1.6 times as long as wide, with inner tufts of penicillate setae and short outer-distal simple seta; second article wider than long, about one-third length of first, with inner distal tuft of penicillate setae and simple seta longer than article width; third article two-thirds length of second with inner and outer distal setae; fourth article slender, tapering, almost as long as second and third articles together, with one distal seta; distal article minute, with four distal setae and single aesthetasc.

Antenna ( Fig. 61B) proximal article compact, naked; second article just shorter than wide, ventral margin produced, without distal apophyses, with mid-ventral seta, shorter laterodistal and dorsodistal seta, dorsal margin densely setulose; third article two-thirds as long as wide, shorter than second article, dorsal margin convex, with stout dorsodistal spine; fourth article just longer than second, with two distal simple setae and mesial and distal penicillate setae; fifth article half as long as fourth with one distal seta; sixth article minute with one very short and four longer distal setae.

Labrum ( Fig. 61C) hood-shaped, apically rounded, setose. Left mandible ( Fig. 61D) with wide, crenulate lacinia mobilis, right mandible ( Fig. 61E) pars incisiva bilobate; left pars molaris ( Fig. 61 D') robust distally with both sharp, slender and short, rounded “teeth”. Labium ( Fig. 61G) simple, densely and finely setose, without palp. Maxillule ( Fig. 61F) with nine distal spines, rows of outer and inner setae on endite, palp not retrieved. Maxilla ( Fig. 61F) linguiform, naked. Maxilliped ( Fig. 61H) endites characteristic of genus, with denticulate outer margin, two ovate spines and long single inner seta; palp first article with outer-distal seta; second article with two simple setae and one shorter denticulate, reflexed spine, distal rows of microtrichia; third article with three marginal and one submarginal inner, finely denticulate setae; fourth article with five distal finely-denticulate setae and fine inner setules; single distal seta on basis comfortably exceeding distal margin of first palp article but not exceeding distal margin of endites.

Cheliped ( Fig. 62A) compact, basis 2.1 times as long as wide, with dorsodistal seta; merus triangular, occupying almost all of ventral margin of carpus, with single mid-ventral seta; carpus 1.75 times as long as wide, with proximal and distal dorsal setae and two longer ventrodistal setae; propodus 1.25 times as long as wide, fixed finger short, half as long as body of propodus (“palm”), with two ventral setae and three setae alongside cutting edge; with lamellate apophyses on cutting edge, terminal spine robust; dactylus with outer margin smooth, two proximal simple setae on cutting edge.

Pereopod 1 ( Fig. 62B) longer than others, coxa simple with long seta; basis slender, arcuate, 4.15 times as long as wide, with dorsal seta in proximal third; ischium compact with single seta; merus slender, with single ventrodistal seta; carpus 0.8 times as long as merus, with one longer and two shorter dorsodistal setae; propodus 1.75 times as long as carpus, with two subdistal setae and fine dorsodistal sharp apophysis; dactylus with dorsoproximal seta exceeding tip of dactylus; unguis slender, curved, twice as long as dactylus, both together 1.1 times as long as propodus. Pereopod 2 ( Fig. 62C) more compact than pereopod 1, basis 2.9 times as long as wide; merus 0.7 times as long as carpus, merus with two ventrodistal setae; carpus with one dorsodistal seta, and one dorsodistal and two ventrodistal curved, finely denticulate spines; propodus twice as long as carpus, and just longer than dactylus plus unguis. Pereopod 3 ( Fig. 62D) similar to pereopod 2.

Pereopod 4 ( Fig. 62E) slightly more robust than anterior pereopods, basis 2.8 times as long as wide with two mid-ventral penicillate setae; merus and carpus subequal in length, each with two ventrodistal curved, finely-denticulate spines, carpus also with two dorsodistal curved, finely-denticulate spines, ventrodistal surface of carpus with rows of microtrichia; propodus 1.4 times as long as carpus, with simple dorsodistal seta, mid-dorsal penicillate seta, two ventrodistal curved, finely-denticulate spines, and row of fine setules along distal margin; dactylus stout, with microtrichia; unguis distinct, curved, with minute ventrodistal denticulation, half length of dactylus, both together 0.6 times as long as propodus. Pereopod 5 ( Fig. 62F) as pereopod 4. Pereopod 6 ( Fig. 62G) as pereopod 4, but propodus with three dorsodistal serrate spines and no dorsal penicillate seta.

Pleopods ( Fig. 62H) all alike, with naked basis, endopod with single inner subdistal plumose seta; exopod without setae on inner margin, proximal seta on outer margin of both rami separated from remaining setae.

Uropod ( Fig. 62I) basis naked, exopod of one segment, over half as long as endopod, with one mesial and two unequal distal setae; endopod of one segment, with mesial and distal tufts of penicillate and simple setae; rami slender.

Male. Unknown.

Etymology. From the Greek tanaos – long and herpes – a creeping thing, the present species being the most elongate yet known in the genus.

Remarks. There are only two described species of Paratanais with a single-segmented uropod endopod, viz. P. intermedius Dojiri & Sieg, 1997 (q.v.) from 98 to 591 m depth in the Santa Maria Basin, California, and P. wanga Bamber, 2008 from 4 to 26 m in Moreton Bay, Queensland. Although the description and figures of P. intermedius are poor, it is distinct from Paratanais tanyherpes sp. nov. in having a more elongate antenna (peduncle articles 2 and 3 clearly longer than wide), the distal seta on the maxilliped basis not reaching the distal margin of first palp article, the merus of the cheliped covering only some 75% of the ventral margin of the carpus, the merus on pereopod 1 shorter than the carpus, and the uropod rami much less elongate. P. wanga is distinct from P. tanyherpes in having the second antennal peduncle article 1.4 times as long as wide, and again the uropod rami much less elongate. In many respects, P. tanyherpes is very close in morphology to the New Zealand species P. tara Bird, 2011 , with which it shares the proportions of the antennule, the setation/spination of the antennule, of many details of the maxilliped, but that species differs in having a two-articled uropod endopod ( inter alia).

Paratanais tanyherpes is further distinguished from these three species, and indeed all others in the genus, in being very elongate, the body being nearly nine times as long as wide (“about 6” times in P. intermedius ; 6.4 times in P. wanga ; up to 7.5 times in P. tara ; eight times as long as wide in the previously most-elongate species, P. martinsi Bamber & Costa, 2009 , q.v.). P. tanyherpes was found throughout the Bass Strait, including in Western Port and Port Phillip Bay, at depths between 0 to 81 m.