Cirolana vanhoeffeni Nierstrasz, 1931

Sidabalok, Conni M. & Bruce, Niel L., 2016, Redescription of three cirolanid isopods (Crustacea: Peracarida) from Indonesia, Zootaxa 4114 (3), pp. 277-290 : 285

Cirolana vanhoeffeni Nierstrasz, 1931

( Fig. 6 )

Cirolana vanhöffeni Nierstrasz, 1931: 153 , figs 16–23.

Cirolana vanhoeffeni .— Bruce, 1986: 200.

Cirolana vanhoffeni .— Brusca, Wetzer & France, 1995: 18.

Not Cirolana vanhöffeni .—Nierstrasz, 1931, figs 26–29 [= Politolana stebbingi (Nierstrasz, 1931) , present study].

Material examined. Holotype ♂ (10.0 mm), Siboga Expedition , 1°58.5'N, 125°0.5'E, station 122, 1155– 1264 m, 17 June 1899 ( ZMA. CRUS.I. 100606).

Supplementary description (male). Body 3.5 times as long as greatest width, dorsal surfaces smooth, widest at pereonite 4, lateral margins subparallel. Rostral point absent. Pereonite 1 and coxae 2–3 each with posteroventral angle rounded; coxae 5–7 with entire oblique carina; posterior margins of pereonites 5–7 smooth. Pleon with pleonite 1 visible in dorsal view; pleonites 3–5 posterior margin smooth; posterolateral angles of pleonite 2 rounded, not posteriorly produced; pleonite 3 with posterolateral margins not extending to posterior margin of pleonite 5, acute; posterolateral margin of pleonite 4 rounded, clearly extending beyond posterior margin of pleonite 5. Pleotelson 1.4 times as long as anterior width, dorsal surface without longitudinal carina; lateral margins straight, margins smooth, posterior margin subtruncate, without median point, with 8 RS.

Antennula peduncle articles 1 and 2 not fused, article 3 being longest, flagellum extending to posterior margin of eye. Antenna peduncle articles 1–3 shortest, articles 4 and 5 are subequal in length, flagellum extending to posterior of pereonite 2.

Frontal lamina pentagonal, longer than greatest width, lateral margins straight, diverging slightly towards anterior, anterior margin rounded, without small median point.

Penes low tubercles.

Uropod rami not extending beyond pleotelson, marginal setae in single tier, apices broadly rounded. Endopod apically not bifid; lateral margin straight; mesial margin strongly convex. Exopod not extending to end of endopod, apically not bifid; lateral margin straight; mesial margin convex.

Female. No female specimens available.

Distribution. Known only from the type locality.

Remarks. Cirolana vanhoeffeni superficially resembles Cirolana lata Haswell, 1882 in lacking eyes, but differs by having a more elongate body, the presence of fine tubercles on the lateral margins of pleonites 2–3, pleonite 4 with a rounded posterolateral margin, pleonite 3 with a less extended posterolateral margin and a pentagonal frontal lamina. Cirolana vanhoeffeni accords with the generic diagnoses for Cirolana , including the lack of a process on the ischium and merus of the inferodistal margin pereopod 1, unflattened pereopod 7, the morphology of antennula and antenna peduncles, low tubercle-like penes and basal attachment of the appendix masculina. The rounded posterolateral margin of pleonite 4 and the weakly extended posterolateral margin of pleonite 3 (not reaching end of pleonite 5) indicates a possible affinity of Cirolana vanhoeffeni to the ‘ Cirolana tuberculate group’, but another distinguishing character for that group, the arrangement of robust setae on the lateral margin of exopod, cannot be determined as all the robust setae are missing and the margins of the rami heavily rubbed. The pleopods and mouthparts are not described as they had been previously dissected from the holotype and were not with the specimen.

Figures

FIGURE 6. Cirolana vanhoeffeni, holotype (10 mm). A, dorsal view; B, lateral view; C, pleonites; D, frons; E, pleotelson and uropods; F, penial openings.