Mirabilicoxa alberti, George, 2001

George, Robert Y., 2001, Desmosomatidae and Nannoniscidae (Crustacea, Isopoda, Asellota) from bathyal and abyssal depths oOE North Carolina and their evolution, Journal of Natural History 35 (12), pp. 1831-1859 : 1837

Mirabilicoxa alberti n. sp.

(®gure 3A±E)

Material examined. Holotype female, length 2.8 mm, maximum width 1.1 mm. USNM Cat. No. 138733.

Type locality. Lower Carolina slope at 3010 m. Eastward Sta. G-8 (7814) .

Etymology. This species is named in honour of the late Prince Albert of Monaco for his important contributions to the study of deep-sea fauna.

Diagnosis of the adult female. Body tapering from anterior to posterior, at its maximum width at the posterior part of the pleotelson. Pleotelson with acute posterolateral spines. Anterior four pereopods with triangular coxal plates that tend to decrease in size from the ®rst to the fourth. First pereopod with one prominent spine on the inner and outer distal margin of merus; carpus with ®ve very long seta-tipped spines. Uropod uniramous, endopod 2.6 times as long as protopod.

Description. Cephalon narrower than the ®rst pereonite, with frontal margin convex, slightly shorter than the length of the anterior two pereonites combined. First and second pereonites subequal. Fourth pereonite longer than the third pereonite. Sixth pereonite semiglobular in shape and about twice as long as seventh pereonite. Pleotelson about as long as sixth and seventh pereonites combined, with distinct sharp posterolateral spines, and posterior margin rounded.

Antennula composed of ®ve articles, with a broad basal article, twice as broad as the second article. Second article elongated, about as long as the terminal three articles combined. Second article with two very elongated setae at the inner distal angle and one moderately long seta at the outer distal angle.

First pereopod with ischium twice as long as merus. Merus with a long spine on both inner and outer distal angle. Carpus broader than the propodus but almost the same length. Inner margin of carpus with ®ve long seta-tipped spines. Propodus lacking such marginal spines except for one small seta at both outer and inner distal angle. Third pereopod with a long basis, longer than ischium and merus combined. Carpus supplied with single long seta on the inner margin and seven long setae on the ventral side. Propodus narrower and shorter than carpus and with four spines on the inner margin. Uropod uniramous, protopod with long distal setae and endopod long, bearing many apical setae.

Remarks. This new species is related to a northern North Atlantic species Mirabilicoxa plana Hessler, 1970 from 3834 m (lat. 37ss50.2¾N and long. 69ss26.2¾W), in the general body shape and in having the posterolateral spines on the pleotelson more laterally directed. But these two species are distinguished from each other in the pattern of setation on the propodus and carpus of the ®rst pereopod. The fundamental character variation between these two species is clearly seen in the uropod which is uniramous in M. alberti but in M. plana the uropod has a vestigial exopod.