Heptanthura kensleyi, 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 : 35-36

Heptanthura kensleyi n. sp. ( Figs 21–23 )

Material examined.– Holotype. Australia. New South Wales, Morna Point (22°47'S, 152°07'E), tide pool open to sea, filamentous red algae, 1–2 m, J.K. Lowry and G.C.B. Poore, 16 Jan 1981 (stn NSW­144), NMV J27640 (juvenile, 5.4 mm, with 2 slides).

Description: Juvenile. Head about as wide as long, narrowest anteriorly, with broad triangular rostrum shorter than anterolateral lobes, with 7 pairs of dorsal setules; eyes present. Pereonites 1 and 2 narrower than others, 4 the longest and 7 about two­thirds as long as 6. Pleonites 1–5 fused, together little longer than pereonite 7; pleonites 1–4 with very short lateral epimera, 2–4 each with 1 short facial seta, pleonite 5 with 3 short facial setae, posterior margin bearing row of about 40 plumose setae; pleonite 6 free from 5. Telson base 0.6 width of widest point, two­thirds way along, dorsally slightly concave, apex rounded; telson with distal submarginal row of 20 setae and other setules dorsally.

Antenna 1 peduncle with stout article 1, short article 2 and narrower article 3; flagellum with short basal article, longer second and minute third, last 2 each with 2 aesthetascs. Antenna 2 broken on only specimen.

Mandible with produced simple incisor, toothed lamina dentata, and truncate molar; mandibular palp article 1 with 1 seta, article 2 twice as long and with 1 seta, article 3 short and with 3 serrate setae. Maxillipedal endite broadly triangular; palp articles generally tapering, articles 1+2 with medial seta, article 3 almost as long, with 2 medial setae, article 4 more tapered, with 1 medial seta, article 5 minute, with 4 distal setae; palp articles each with 1–2 minute lateral scales.

Pereopod 1 compact, stout; merus broader than long and than more distal articles, with 1 posterodistal and 2 anterodistal setae; carpus triangular, with 2 posterodistal setae; propodus tapering, margin of palm with 2 simple setae, distal corner of palm with 2 simple and 1 setulate setae, mesial face with setulate seta, and anterodistal margin with 2 simple setae; dactylus stout, not as long as palm, mesial face with pectinate setae, 5 stout simple setae and bicuspidate auxillary seta at base of unguis. Pereopod 2 much less robust than pereopod 1; merus cupping triangular carpus, with 1 posterodistal and 2 anterodistal setae; carpus not reaching anterior margin, with 2 posterodistal setae; propodus tapering, with 1 pappose seta on anterior margin, palm with complex distal seta (acute apex and 4­toothed basal blade) and simple seta nearby, anterodistal margin with 2 setae; dactylus with simple stout seta at base of unguis and other simple setae on mesial and lateral faces. Pereopod 3 similar but slightly smaller than pereopod 2. Pereopod 4 with stout basis; narrower ischium; swollen merus with 1 seta on posterodistal margin and 2 on mesial margin; carpus with short free anterior margin, posterodistal corner with complex seta (acute apex, 3­ toothed basal blade and lateral flagellum) and simple seta; propodus rectangular, end of palm with complex seta (acute apex, 2­toothed basal blade and lateral flagellum) and simple seta; dactylus with simple stout seta at base of long curved unguis and other simple setae on mesial and lateral faces. Pereopods 4–6 similar in length and setation to pereopod 4 but propodi successively narrower. Pereopod 7 also narrower; carpus with complex seta having acute apex and bifid basal blade; propodus tapering, palm with 1 simple strong seta and 1 setulate strong seta near base of complex seta, anterior margin with 2 setulate setae and pappose seta laterally.

Pleopod 1 operculiform, covering all other pleopods; endopod two­thirds as wide and little longer than exopod, parallel­sided, with 14 distal plumose setae; exopod oval, 2.5 times as long as wide, with 23 marginal plumose setae. Pleopod 2 about two­thirds as long as pleopod 1, others shorter; endopods with 5–7 distal plumose setae; exopods broader, with 13–16 plumose setae and lateral fine setae. Uropodal endopod reaching near end of telson, suture with peduncle strongly oblique, about 1.4 times as long as wide, margin irregularly lobate and setose; exopod with irregularly lobate and setose margin, with a short dorsal lobe not exceeding distal apex.

Male and female. Unknown.

Etymology: For Brian Kensley, Washington, DC, USA, in recognition of his contribution to the systematics of anthuroid isopods.

Distribution: Australia, central New South Wales; 1–2 m depth (known only from type locality).

Remarks: This species is placed in Heptanthura on the basis of fused pleonites 1–5, the special complex dentate setae on the propodi of pereopods 1–7 and carpi of pereopods 4–7. It also shares fused articles 1 and 2 of the maxillipedal palp, a situation rare in other anthuroids. H. kensleyi n. sp. is similar to the type species, H. novaezelandiae Kensley, 1978 , differing in the shorter dorsal lobe on the uropodal exopod.

Figures

FIGURE 21. Heptanthura kensleyi n. sp. Holotype, NMV J 27640. Scale bar = 1 mm.

FIGURE 22. Heptanthura kensleyi n. sp. Holotype, NMV J 27640.

FIGURE 23. Heptanthura kensleyi n. sp. Holotype, NMV J 27640.