Natatolana nitida ( Hale, 1952 )

Keable, Stephen J., 2006, Taxonomic Revision of Natatolana (Crustacea: Isopoda: Cirolanidae), Records of the Australian Museum 58 (2), pp. 133-244 : 208

Natatolana nitida ( Hale, 1952)

Cirolana nitida Hale, 1952: 25 , fig. 1.– Kussakin, 1967: 224.– Carvacho, 1977: 176.– Kensley, 1980: 159.–Kussakin & Vasina, 1982a: 261.–1982b: 329, 335–336.

Natatolana nitida .– Bruce 1981: 958.– 1986: 222.– Brandt, 1988: 102.– Brusca et al., 1995: 82.– Kensley, 2001: 230.

Type material. Holotype: 3, 22 mm, SAMA C3279 . Allotype: ♀, 24 mm, SAMA C3281 . Paratypes: 11, SAMA C3280 . All examined. Type locality: just south of Kerguelen, 49°50'S 69°33'E, [B.A.N.Z.A.R.E. Station 47 First Cruise, 7 Feb. 1930, large rectangular dredge], 150 m.

Diagnosis. Eyes: well developed; elongate, length c. 2× height. Interocular furrow: weakly developed, indistinct and not extending across the cephalon. Frontal lamina: lateral margins sinuate. Antenna: c. 0.35× as long as body, reaching to three quarters of the way along pereonite 3. Coxal plates: furrows strongly developed, on all coxae. Coxa 2 with anteroventral corner produced into an acute tooth. Pleonite 4: posterodorsal margin strongly concave proximal to meeting posteroventral margin at apex; apex forming a narrow acute point. Pleotelson: broad, length 0.89× basal width; anterodorsal depression absent; anterolateral margins almost straight and angling posteriorly toward the midline; posterolateral margins straight, markedly angled to anterolateral margins and meeting at an obtuse angle or concave; apex produced into a large point; with 8–10 RS. Pereopod 2: propodus with 3 RS on palm. Pereopod 3: propodus with 2 RS on palm. Pereopod 7: basis of medium breadth, width 0.47–0.52× length; distance between anterior margin and medial carina less than between posterior margin and medial carina; posterior margin with setae along entire length. Penes: present. Pleopod 2 appendix masculina: extending subequal with tip of endopod, 0.96–0.98× length of endopod; margins twisted; broad; apex not at angle to adjacent margins, acute or bluntly rounded. Uropods: exopod subequal to endopod, 0.91× the length of the endopod.

Size. Adults to just over 30 mm.

Remarks. Natatolana nitida and N. obtusata are the only species of Natatolana in which males have an excavate medial margin on the endopod of pleopod 2 and a distinctly twisted appendix masculina. Natatolana nitida also has a distinct acute tooth on the anteroventral corner of coxa 2 that is otherwise known only in N. corpulenta . These characters distinguish N. nitida from all other species in the genus. Natatolana obtusata is most similar but has the posterodorsal margin of pleonite 4 sinuate, as well as lacking the acute tooth on the anteroventral corner of coxa 2. Natatolana intermedia is also similar but has the pleotelson with convex posterodorsal margins and a slender, strongly curved appendix masculina, as well as lacking the acute tooth on the anteroventral corner of coxa 2.

Distribution. Kerguelen Islands, Crozet Islands, Southern Ocean.At depths of 40–334 m (Kussakin & Vasina, 1982b).