Ambicholestes (Austrolestes) berentsae, Just, 1998

Just, Jean, 1998, Siphonoecetinae (Crustacea: Amphipoda: Ischyroceridae) 7: Australian Concholestids, Ambicholestes n. gen., with a Description of Six New Species, and a New, Restricted Diagnosis for Caribboecetes Just, 1983, Records of the Australian Museum 50 (1), pp. 27-54 : 42-47

Ambicholestes (Austrolestes) berentsae n.sp.

Figs 13 -16

Concholestes spp., Stephenson & Cook (1977, partim, see Just 1988), Stephenson, Cook & Newlands (1978, partim, see Just 1988).

Material examined. HOLOTYPE: male, 5.6 mm, Jervis Bay, New South Wales, off Moona Moona Creek , 35°03'S 150042'E, 8 m, air-lift of bottom sediment, P.B. Berents, 29 January 1983, AM P44601 . PARATYPES: 265 specimens. Jervis Bay (136): SE of Huskisson, offMoona Moona Creek, 8 m, fine sand with detritus to coarse shelly, broadly rippled sand, just inside low rock reef covered with large brown algae, hand dredge ( SCUBA), J. Just, 15 November 1984, Stn AU-65, AM P44602 (3) and ZMUC (5). North side of Plantation Point, 35°04'S 150032'E, 5 m, wide patches of silty sand with Halodule between rock reefs, hand dredge ( SCUBA), J. Just, 17 November 1984, Stn AU-70, AM P44603 (3) . North side of Plantation Point, 35°04'S 150032'E, 5 m, wide patches of silty sand with Halodule between rock reefs, hand dredge ( SCUBA), J. Just, 17 November 1984, Stn AU-71, AM P44604 (3) . Off Moona Moona Creek , 53°03'S 150042'E, 8 m, sand, airlift, P.B. Berents, 17 November 1981, AM P44605 North Harbour, at base ofjetty at Store Beach , 33°51'S 151°16'E, 3 m, sand, large amount of fine shell fragments, some detritus, Halodule and various low algae, hand dredge ( SCUBA), J. Just, 26 September 1984, Stn AU-59, AM P44610 (57) and P44611 (9). North Harbour, at base of jetty at Store Beach , 33°51'S 151°16'E, 3 m, sand, large amount of fine shell fragments, some detritus, Halodule and various low algae, hand dredge ( SCUBA), J. Just, August 1986, AM P44612 (32) . Bass Strait (27): western Bass Strait, 64 km WNW of Cape Farewell, King Island , 39°31'S, 143°12'E, 122 m, medium sand, Smith-McIntyre grab/pipe dredge, G.C.B. Poore, HMAS "Kimbla", 11 October 1980, Stn BSS 83, NMV J9535 (1) . Eastern Bass Strait, 94 km NE ofNorth Point, Flinders Island , 38°53.7'S 147°55.2'E, 71 m, medium sand, WHOI epibenthic sled, R. Wilson , RV " Tangaroa ", 15 November 1981, Stn BSS 171 S, NMV J9538 (1) . Eastern Bass Strait, 70 km N of North Point, Flinders Island , 39°05.2'S 147°56.6'E, 62 m, shelly sand, WHOI epibenthic sled, R. Wilson , RV " Tangaroa ", 17 November 1981, Stn BSS 172 S, NMV J9531 (1) . Eastern Bass Strait, 70 km N ofNorth Point, Flinders Island , 39°05.2'S 147°56.6'E, 62 m, shelly sand, grab, sled or trawl (see label), R . Wilson , RV " Tangaroa ", 17 November 1981, Stn BSS 172, NMV J9539 (1) . Western Bass Strait , 15 km S of Port Fairy, 38°32.0'S 142°28.6'E, 52 m, medium sand, grab, sled or trawl (see label), R . Wilson , RV " Tangaroa ", 20 November 1981, Stn BSS 187, NMV J9543 (1). Western Bass Strait , 80 km SSE of Cape Otway, 39°26'S 142°57'E, 113 m, medium sand, Smith­ McIntyre grab/pipe dredge, G.C.B. Poore, HMAS "Kimbla", 9 October 1980, Stn BSS 67, NMV J9534 (1). Western Bass Strait , 31 km SSW of Cape Otway, 39°08'S 143°24'E), 77 m, medium sand, Smith-McIntyre grab/naturalist's dredge, G.C.B. Poore, HMAS "Kimbla", 8 October 1980, Stn BSS 56, NMV J9533 (1). Central Bass Strait , 36 km S of Cape Otway, 39°03'S 143°51'E, 85 m, medium sand, carbonate, Smith-McIntyre grab/ naturalist's dredge, G.C.B. Poore, HMAS "Kimbla", 7 October 1980, Stn BSS 47, NMV J9532 (1) . Central Bass Strait , 38 km SW of Cape Paterson, 38°56.4'S 145°16.6'E, 70 m, fine sand, WHOI epibenthic sled, R. Wilson , RV " Tangaroa ", 12 November 1981, Stn BSS 155 S, NMV J9537 (6) . Central Bass Strait , 38 km SW of Cape Paterson, 38°55.5'S 145°17.0'E, 70 m, fine sand, Smith-McIntyre grab, R . Wilson , RV " Tangaroa ", 12 November 1981, Stn BSS 155 G, NMV J9536 (3) . Eastern Bass Strait , 20 km SE of Port Albert, 38°43.4'S 146°56.9'E, 26 m, WHOI epibenthic sled, R. Wilson , RV " Tangaroa ", 18 November 1981, Stn BSS 178 S, NMV J9541 (3) . Eastern Bass Strait , 20 km SE of Port Albert, 38°43.4'S 146°56.9'E, 26 m, WHOI epibenthic sled, R. Wilson , RV " Tangaroa ", 18 November 1981, Stn BSS 178 S, NMV J9542 (1) . Eastern Bass Strait , 50 km SE of Port Albert, 38°54.3'S l 47°13.4'E, 58 m, coarse shell, grab, sled or trawl (see label), R . Wilson , RV " Tangaroa ", 18 November 1981, Stn BSS 176, NMV J9540 (6) . Other material: Jibbon , New South Wales, 34°05'S 151°10'E, 50 m, sand, dredge, K. Sheard, CSIRO 12 September 1943, AM P44219 (1) . East of Cape Banks , New South Wales, 33°52'S 151°23'E, 88 m, 2.5 m sledge dredge, R . Springthorpe and P.H. Colman, FRV "Kapala", Stn K80- 20--11, 11 December 1980, AM P44614 (3).

Fig.13. Ambicholestes(Austrolestes) berentsaen.sp.,holotype.

46 Records of the Australian Museum (1998) Vol. 50 ADDITIONAL MATERIAL. Moreton Bay , Queensland (several hundred): Middle Banks , 19 m, sand, September 1972, S. Cook, Stn 9, QM W6345 (5- 10 specimens, 27 abodes) . Middle Banks, 22 m, sand, September 1972, S. Cook, Stn 19, QM W6346 (several hundred) . Middle Banks 1982, Zool. Dep., Univ. of Queensland, Stn lC, QM W1 l660 (1). Middle Banks, July / August 1982, I. Poiner, QM W1 l662 (10). Middle Banks, September 1976, Zool. Dep., Univ. of Queensland, QM Wl 1663 (30). Middle Banks, October 1976, Zool. Dep., Univ. of Queensland, QM W1 l664 (7). Middle Banks, December 1976, Zool. Dep., Univ. of Queensland, QM W1 l665 (7). Middle Banks, June 1974, S. Cook and S. Newlands, QM W20646 (1).

Diagnosis. Austrolestes with rostrum present in normal position. Cephalon along dorsal midline as long as or up

to 10% longer than pereonite 1. Cephalon and body with setules in distinct transverse rows.

Further description (type material). Rostrum pointed, triangular. Antenna 1 peduncle article 1 with 1 (occasionally 2) recurved robust setae ventrally in proximal half. Antenna 2 article 3 without robust setae; ventroapical projection of article 2 wider than long, evenly rounded, with apical row of long setae. Male antenna 1 longer than combined cephalon and pereon by approximately llz pieon length, with up to 11 flagellar articles. Male antenna 2 about as long as cephalon, pereon and pleon combined.

Coxal plates 5 and 6 with posterior lobe rounded to bluntly triangular (plate 5 in particular); plate 5 anterior margin with short row of long setae. Pleonal side plates 1 and 2 evenly rounded.

Mandibular palp overreaching mandibular cutting edge by about 112 palp length, entire lateral surface densely covered by microsetules.

Pereopod 1 article 5 with 1 (occasionally 2) posterior robust setae; article 6 with posterodistal tooth and up to 8 posterior robust setae. Pereopod 2 article 2 anterior margin straight, fringed with moderately long, simple setae; article 6 with up to 6 posterior robust setae. Pereopods 5 and 6, article 2 anterodistally with row of up to 10 long setae, article 5 with up to 15 short robust setae in crescent.

Uropod 1, peduncle with up to 15 distal robust setae; outer ramus about 4112 times longer than broad, with up to 13 double and triple rows of dorsolateral robust setae; inner ramus barely less than 112 length of outer ramus, with up to 11 lateral and apical robust setae.

Urosomites 1 and 2 free; urosomites 2 and 3 normally free, but in some specimens part fusion is apparent; urosomite 3 and telson fused dorsally, but often with distinct subcuticular line of demarcation.

Size. Largest male: 7.7 mm; largest female: 4.8 mm.

Colour (live animals). Overall yellowish-orange. Cephalon and first two pereonites with red-brown mottling, rest of pereon and most of pleon with whitish mottling. Pereopods colourless transparent, anterior ones in large specimens with brownish tinge. Frons and mouthparts faintly brownish. Antenna 1 semitransparent whitish, with faint orange-yellow core in peduncle; peduncle and flagellum with whitish longitudinal line middorsally. Antenna 2 generally as 1, with same core colour in peduncle; peduncle articles 3-5 with 3 longitudinal lines of white and 3 of orange-brown.

Moreton Bay population. Specimens from Moreton Bay have not been included in the type material, although they identify to A. berentsae in the key presented. Adult specimens are significantly smaller than the type material (largest male: 4.8 mm; largest female: 3.2 mm; largest ovigerous female: 2.9 mm). Pereopods 1 and 2 are more robust, with articles 5 and 6 slightly broader relative to the length than in the type material. Generally specimens from Moreton Bay have fewer robust setae on pereopods and uropods. In some specimens the telson is separate from urosomite 3, in others partly or fully fused as in the type material.

The difference in size between specimens of the Moreton Bay population and the more southerly type material may reflect environmental differences, hydrographic regimes in particular. Morphological differences outlined may be partly size dependent and partly of a clinal nature. However, material is required from in between central New South Wales and Moreton Bay as well as around and outside Moreton Bay and north perhaps to the southern reaches of the Great Barrier Reef in order to fully assess the status of the Moreton Bay population here referred to A. berentsae . Biology. On fine to coarse, often shelly, detritus-covered sand. In shallow water also in Halodule sea-grass beds. The predominant abode used is small prosobranch shells furnished with a short tube with coarse shell fragments (86 out of 110 abodes from Jervis Bay and Port Jackson, the several hundred abodes from Moreton Bay and the only 3 abodes found in the material from the Bass Strait). Some specimens from Jervis Bay and Port Jackson occupied small scaphopod shells (5) or polychaete tubes (19).

Distribution (all populations). Eastern Australia: Moreton Bay, Queensland, to Bass Strait; 3-122 m depth.

Etymology. This species is named for Dr P. (Penny) B. Berents, Australian Museum, in recognition of her work on the Jervis Bay fauna and her help during my field work in New South Wales, Jervis Bay in particular.