Natatolana pastorei ( Giambiagi, 1925 )

Keable, Stephen J., 2006, Taxonomic Revision of Natatolana (Crustacea: Isopoda: Cirolanidae), Records of the Australian Museum 58 (2), pp. 133-244 : 213

Natatolana pastorei ( Giambiagi, 1925)

Cirolana magellanica Pfeffer, 1887: 58 , nomen nudum.– Hansen, 1890: 357.– Bruce, 1986: 218.–Wägele & Bruce, 1989: 95

Cirolana pastorei Giambiagi, 1925: 4 , pl. 1, pl. 3, fig. 3.

Natatolana pastorei .– Bruce, 1981: 958.– 1986: 97, 222.–Wägele & Bruce, 1989: 95.– Brusca et al., 1995: 82.–Lorenti & Mariani, 1997: 255.

? Cirolana oculata .– Schultz, 1977: 72, figs. 3–4 [figures labelled C. albinota ]. [possible mis-identification of Natatolana oculata Vanhöffen, 1914 ].

Not Cirolana pastorei .– Monod, 1931: 22 [mis-identification = Natatolana sp.].

Type material. Syntypes: 9, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires Nr 12690 (not examined). Type locality: San Sebástian , Tierra del Fuego [c. 53°9'S 68°18'W] .

Material examined. Chile: ♀ , 3, AM P47134, Fiordo Quintupeu, 42°10'S 72°25'W, A. Carvacho; 3, USNM Acc. No. 288382, off south tip of Vancouver Island , 51°27.5'S 74°03'W, epibenthic dredge, 700–920 m, D.L. Pawson, 10 Oct. 1969, HERO Cruise 69-5 stn 213; 3, USNM Acc. No. 288382, 53°31'S 70°33'W, 270 m . South Georgia: 233, ♀, ZMUC CRU132 , 54°27.3'S 35°47.5'W, 50 m .

Diagnosis. Interocular furrow: moderately developed, distinct but not extending across the cephalon. Frontal lamina: lateral margins medially constricted. Antenna: c. 0.4× as long as body, reaching to posterior of pereonite 4. Coxal plates: furrows strongly developed, on all coxae. Pleonite 4: posterodorsal margin strongly concave proximal to meeting posteroventral margin at apex; apex forming a narrow acute point. Pleotelson: broad, length 0.92× basal width; anterodorsal depression absent; anterolateral margins convex; posterolateral margins convex; apex produced into a small point; with 10–16 RS. Pereopod 2: propodus with 3 RS on palm. Pereopod 3: propodus with 2 RS on palm. Pereopod 7: basis broad, width 0.54× length; distance between anterior margin and medial carina less than between posterior margin and medial carina; posterior margin with setae on distal half. Penes: present. Pleopod 2 appendix masculina: extending beyond tip of endopod; margins straight; slender; apex recurved, bent slightly medially, tapered to a finely acute point. Uropods: exopod subequal to endopod, 1 × length of endopod.

Variation. Wägele & Bruce (1989) state that the antennule flagellum is not much longer than the peduncle. Their illustration, however, shows the peduncle longer than the flagellum and this is the case in the material examined. The specimens from southern Chile ( AM P47134) have the apex of the pleotelson less produced than in other material examined. One specimen from southern Chile ( USNM Acc. No. 288382) has only 10 robust setae on the pleotelson rather than the 12–16 recorded by Wägele & Bruce (1989) .

Size. Immature adults 27–34 mm, males 30.5–33 mm (Wägele & Bruce, 1989).

Remarks. Natatolana pastorei is similar to N. meridionalis and N. oculata but differs most noticeably in having the dorsal posterolateral margin of pleonite 2 projecting subequal to the ventral posterolateral margin (not projecting posterior to the ventral margin), pereonite 1 and coxa 2 with straight or slightly convex posterior margins (never sinuate) and the appendix masculina tapered to a finely acute point (not bluntly rounded).

The possible record from southern Argentina by Schultz (1977) (as Cirolana oculata , figures labelled C. albinota ) is discussed under remarks for N. meridionalis .

Distribution and ecology. Straits of Magellan; South America: between Hale Cove, Argentina to Punta Arenas, Chile and from San Sebastián, Argentina. In shallow sublittoral sediments (Wägele & Bruce, 1989). New records reported here are from the vicinity of South Georgia and to depths of 920 m. Scavenger.