Natatolana thalme Bruce 1986

Natatolana thalme Bruce, 1986: 113, figs. 79, 80.–Springthorpe & Lowry, 1994: 62.– Keable, 1995: 43.– Brusca et al., 1995: 82.–Keable, 1997: 268.– Bruce et al., 2002: 153.

Type material. Holotype: 3, QM W6292 (not examined). Paratypes: QM W6288, W6291–6293, W9848–9852 (not examined); AM P32382 (examined). Type locality: Middle Banks, Moreton Bay, Queensland, Australia, 27°06'S 153°16'E.

Material examined. Listed by Keable (1997).

Diagnosis. Interocular furrow: moderately developed, distinct but not extending across the cephalon. Frontal lamina: lateral margins medially constricted. Antenna: c. 0.34× as long as body, reaching to posterior of pereonite 3 (not pereonite 2 as described by Bruce [1986]). Coxal plates: furrows moderately developed, on all coxae. Pleonite 4: apex rounded. Pleotelson: narrow, length 1.05× basal width; anterodorsal depression absent; anterolateral margins almost straight and angling posteriorly toward the midline, or convex; posterolateral margins straight, markedly angled to anterolateral margins and meeting at an acute angle or convex; apex produced into a small point; with 4–6 RS. Pereopods 2–3: propodus without RS on palm. Pereopod 7: basis of medium breadth, width 0.49– 0.52× length; distance between anterior margin and medial carina greater than between posterior margin and medial carina; posterior margin with sparse setae along entire length. Penes: absent. Pleopod 2 appendix masculina: extending subequal with tip of endopod; margins very slightly curved laterally; slender; apex not at angle to adjacent margins, with a distinct acute projection. Uropods: exopod slightly shorter than endopod, 0.84× the length of the endopod.

Variation. Type material of Natatolana thalme has four robust setae on the margins of the pleotelson, Keable (1997) reported that this was the most common number of robust setae but that some specimens may have six.

Sexual dimorphism. Bruce (1986) reported that males have fewer robust setae on the pereopods than females. This may reflect the difference in size of the material examined.

Size. Males to c. 6.9 mm, females to c. 9.5 mm, mancas to c. 6.0 mm (Bruce, 1986).

Remarks. Natatolana thalme is most similar to N. gallica. It differs most noticeably from that species in having the posterolateral margins of the pleotelson noticeably angled to the anterolateral margins (convex and smoothly continuous with the anterolateral margins in N. gallica), incomplete coxal furrows, sparse setae along the length of the posterior margin of the basis of pereopod 7 (dense in N. gallica) and in lacking robust setae on the palm of the propodus of pereopods 2 and 3 (often present in N. gallica).

Distribution and ecology. Australia: northern Western Australia, Northern Territory, northern Queensland south to Moreton Bay. Intertidal to 83 m depth. Scavenger.