Natatolana arrama Bruce, 1986

Keable, Stephen J., 2006, Taxonomic Revision of Natatolana (Crustacea: Isopoda: Cirolanidae), Records of the Australian Museum 58 (2), pp. 133-244 : 156

Natatolana arrama Bruce, 1986

Natatolana arrama Bruce,1986:108 , fig.74.–Springthorpe & Lowry, 1994: 38.– Brusca et al., 1995: 79.– Bruce et al., 2002: 149.

Type material. Holotype: ♀, 11.1 mm, AM P30363 . Paratype: AM P30362. All examined. Type locality: south of Portland, Victoria, Australia, 38°52'S 141°50'E, 77 m.

Material examined. New South Wales: 21, AM P47468, east of Coffs Harbour , 30°17.49'S 153°13.90'E, 45.4 m, 11–12 Aug. 1993, SEAS NSW-873; 30, AM P47469, off Providential Head, 34°44'S 150°39'E, baited trap, 45–50 m, S. Keable, A. Parker & J. Lowry, 14–15 Jan. 1991, PIO-107; 502, AM P44317, off Wollongong, 34°26.54'S 150°57.98'E, 50 m, 28 Mar. 1994, SEAS NSW-956 . Tasmania: 175, AM P47470, about 800 m east of Point Geographe, Freycinet Peninsula , 42°17'S 148°18.8'E, baited trap, 45 m, J.K. Lowry & S.J. Keable, 30 April–1 May 1991, TAS-337 .

Diagnosis. Interocular furrow: moderately developed, distinct but not extending across the cephalon. Frontal lamina: lateral margins straight, narrowing anteriorly. Antenna: c. 0.24× as long as body, reaching to posterior of pereonite 2. Coxal plates: furrows moderately developed, on all coxae. Pleonite 4: apex slightly rounded. Pleotelson: broad, length 0.93× basal width; anterodorsal depression absent; anterolateral margins convex; posterolateral margins convex; apex produced into a small point; with 4 RS. Pereopods 2–3: propodus without RS on palm. Pereopod 7: basis broad, width 0.68× length; distance between anterior margin and medial carina greater than between posterior margin and medial carina; posterior margin with setae along entire length. Penes: absent. Pleopod 2 appendix masculina: extending beyond tip of endopod; margins straight or very slightly curved laterally; slender; apex recurved, bent slightly medially, bluntly rounded. Uropods: exopod slightly shorter than endopod, 0.82× the length of the endopod; lateral margin without RS.

Size. Adults to c. 12.6 mm.

Remarks. This is the first record of a male specimen of Natatolana arrama . Bruce (1986) appears to have illustrated and described pereopod 6 of this species rather than pereopod 7 as stated. The anterior margin of the basis of pereopod 7 is sinuate and the posterior margin convex— not both strongly convex as originally described.

Using the key provided by Bruce (1986) this species can only be reached if it is assumed in couplet 21 that it has six or more robust setae on the pleotelson, whereas it only has four. Natatolana arrama is most readily identified by the lack of robust setae on the uropod exopod lateral margin combined with straight lateral margins of the frontal lamina that converge anteriorly to form an unexpanded and acute apex.

Distribution and ecology. Australia: central New South Wales, off the east coast of Tasmania, Bass Strait (off Portland, Victoria, and Eucla, South Australia). At depths of 45– 77 m. Scavenger.