Panathura hicksi, Poore, Gary C. B., Lew, Helen M. & Ton, 2002

Poore, Gary C. B., Lew, Helen M. & Ton, 2002, Expanathuridae (Crustacea: Isopoda) from the Australian region, Zootaxa 82, pp. 1-60 : 46-50

Panathura hicksi n. sp. ( Figs 28–30 )

Material examined.– Holotype. Australia. Victoria, Cape Otway (38°52'S, 143°31'E), W.F. Seed, 25 Jan 1967, NMV J17178 (juvenile, 4.4 mm, 2 slides). Paratypes. Type locality, NMV J17179 (1 female, 1 juvenile, 2 slides); J17183 (1 female). Australia. Victoria, Aireys Inlet (38°28'S, 144°06'E), globular green weed, W.F. Seed, Jan 1963, NMV J17181 (3 submales, 3 juveniles); J17182 (1 male, 1 slide); on Sphacelaria , 29 Dec 1963, J17185 (1 juvenile); J17201 (1 juvenile); on Galeolaria tubes, Dec 1961, J17186 (1 juvenile); on sponges, Dec 1961, J17187 (2 juveniles). Victoria, Apollo Bay (38°45'S, 143°41'E), Macrocystis, W.F. Seed , 28 Dec 1970, NMV J17184 (3 submales, 10 juveniles).

Other material: Australia. New South Wales. Morna Point (32°47'S, 152°07'E), AM P41460, (2 females, 7 mancas); P41459, (2 juveniles); P41461, (2 females, 14 mancas); P41458, (1 female). South Australia. Sellicks Beach, underside of boulders on reef, NMV J17189 (12 juveniles). West I., N side (35°37'S, 138°36'E), NMV J17190 (7 females). Tasmania. Marion Bay, TM G1714, (1 juvenile). Variety Bay (43°12'S, 147°24'E), NMV J17180 (8 juveniles). Fancy Point, NMV J17191 (10 juveniles). Tinderbox, NMV J17196 (3 juveniles); J17197 (1 juvenile); J17198 (1). Cape Portland, NMV J17199 (1 female). Ile des Phoques (42°25'S, 148°10'E), NMV J17200 (1 submale). Bicheno, granite reef (41°53'S, 147°18'E), NMV J17236 (3); J17237 (1). Victoria. Western Port (38°27.53'S, 145°8.59'E), NMV J17188 (1 juvenile). Cape Paterson (38°41'S, 145°36'E), NMV J17192 (2 females); J17193 (1 female). 75 m SW of Eagles Nest, Venus Bay (38°40'S, 145°40'E), NMV J17194 (1 female). "Harry's Hole", W side of Twin Reefs, Venus Bay (38°41'S, 145°39'E), NMV J17195 (1 female).

Description: Juvenile. Head little wider than long, tapering anteriorly, with obscure broad rostrum, with 4 pairs of lateral setae; eyes small, dorsal. Pereonites wider more posteriorly, 2 the longest and 7 half length of pereonite 6. Pleonites 1–4 of approximately equal length, 5 twice as long, 7 longer, 1–6 almost as long as pereonites 6–7, pleotelson longer than pereonites 6–7, pleonite 5 with c. 20 marginal plumose setae laterally. Telson base strongly waisted, half width of widest point near apex; lateral margin almost parallel but slightly excavate; dorsally concave; apex broadly rounded, with 1 pair of short setae and, on each side starting from middle, 1 short, 2 long, and 4 or 5 well spaced short setae.

Head, pereon and pleonites with weak scattered dorsal brown pigment spots.

Antenna 1 peduncle with stout article 1, narrower articles 2 and 3; flagellum as long as last peduncle article, of short article 1 with pappose seta, article 2 longer, articles 3 and 4 minute, with 0, 0, 1, 2 aesthetascs. Antenna 2 peduncle longer than antenna 1, article 2 not produced anteroventrally, articles 3 and 4 short, 5 longer than wide; flagellum of 5 articles, first longest.

Mandible with weakly produced incisor, truncate lacinia mobilis on right side, lamina dentata of 4 or 5 partially fused blunt spines; molar process blunt; palp article 1 short with 1 seta, article 2 longer than 1, with 1 seta near midpoint and 1 distal seta, article 3 about one­third length of 2, with 3 distal setae. Maxillipedal endite reaching to end of palp article 3, rounded, with 4 distal setae; palp articles 1–3 broad, 2 and 3 fused, article 2 with 1 mesial seta, article 3 with 2 simple mesial setae and 1 lateral seta, article 4 tapering and with 2 mesial and 1 stout lateral setae, article 5 short and with 4 apical setae.

Pereopod 1 subchelate, with basis narrower than in pereopod 2 but stouter than in more posterior limbs; carpus triangular, with 3 setae on posterior margin; propodus twice as long as wide, palm axial, with blunt denticles, with 3 stout setae, mesial face with 3 setae, distal ones strongest; dactylus weakly closing on palm, unguis about half its length. Pereopod 2 merus cupping triangular carpus; carpus not reaching anterior margin, with weakly setose posterior margin; propodus weakly swollen, palm with blunt denticles and distal spiniform seta, 1 fine palmar seta and 3 mesially. Pereopod 3 similar to pereopod 2. Pereopods 4–6 similar; carpus triangular; carpus and propodus each with 2 distal short spiniform setae and few finer setae; dactylus weakly curved, unguis half length. Pereopod 7 carpus slightly longer than in more anterior pereopods; carpus with 2 spiniform setae; propodus with 1 distal spiniform seta and finer setae mesially, plus 2 anterodistal doublepectinate setae.

Pleopod 1 operculiform, endopod half as wide and little longer than exopod, distally setose; exopod twice as long as wide, marginally setose. Pleopods 2–5 about three­quarter as long as pleopod 1; endopods longer, more rectangular and narrower than exopods, distally truncate and setose; exopods distally and laterally setose. Uropodal endopod shorter than peduncle, reaching to end of telson; endopod 1.3 times as long as wide, distally and laterally setose; exopods meeting in midline, 1.7 times as long as wide, with shallow marginal excavation, posteriorly rounded­truncate, c. 20 marginal setae.

Female. Oostegites on pereopods 2–5 (one individual with single embryo as long as pereonites 3–6 of adult female).

Male. Eyes enlarged. Antenna 1 peduncle article 1 longer than wide; flagellum of 10 articles, proximal ones especially shortened and with row of numerous aesthetascs laterally, distal ones narrower, with 1–2 aesthetascs. Antenna 2 peduncle and flagellum more elongate than in juvenile. Pereopods more elongate than in juvenile. Pereopod 1 propodus with 4 mesiopalmar strong setae. Pereopod 2 propodus with 2 palmar strong setae. Pleopod 1 weakly operculiform. Pleopod 2 with appendix masculina 1.4 times as long as endopod, with apical hook; exopod 2­articled.

Size: Both sexes to 5.0 mm.

Distribution: Southern New South Wales, Victoria, Tasmania and South Australia, intertidal and subtidal.

Etymology: For Lieutenant Zachary Hicks (1739–1771), Second Lieutenant with Captain James Cook on the voyage of H.M.S. Endeavour to the South Pacific in 1768–1771, who died at sea, and for whom Point Hicks, Victoria is named.

Remarks: Panathura hicksi n. sp. is commonly encountered in shallow algal communities of south­eastern Australia. It is recognisable by the short pleonites and broad telson.

Figures

FIGURE 28. Panathura hicksi n. sp. Holotype, NMV J 17178. a, male paratype, NMV J 17182. Only one of each row of aesthetascs on antenna 1 drawn. Scale bar = 1 mm.

FIGURE 29. Panathura hicksi n. sp. Holotype, NMV J 17178. a, male paratype, NMV J 17182.

FIGURE 30. Panathura hicksi n. sp. Holotype, NMV J 17178. a, pleopods 1 and 2, male, NMV J 17182.