Austromaera mastersii (Haswell, 1879a)

Lowry, JK & Springthorpe, RT, 2005, New and Little-known Melitid Amphipods from Australian Waters (Crustacea: Amphipoda: Melitidae), Records of the Australian Museum 57, pp. 237-302 : 241-244

Austromaera mastersii (Haswell, 1879a)

Figs. 1–4

Megamaera mastersii Haswell, 1879a: 265 , pl. 11, fig. 1.–Haswell, 1882: 258.–Haswell, 1885: 105.

Maera mastersii .–Stebbing, 1899: 426.–Stebbing, 1906: 439.– Stebbing, 1910a: 642.–?Chilton, 1921b: 72 (southern Australia).

Not Moera mastersii .–Chilton, 1911: 564 (Kermadec Islands) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).

Not Maera mastersi .–Thomson, 1882: 235 (in part, part = M. quadrimana ) (New Zealand).–Sheard, 1936: 177, fig. 3 (South Australia) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).–Sheard, 1937: 24 (South Australia) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).– Sivaprakasam, 1969: 36, fig. 1 a–g [= L. mannarensis (Sivaprakasam, 1970) , according to Krapp-Schickel, 2003].– J.L. Barnard, 1972a: 226, fig. 132 (southern Australia) (= L. leo Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).– J.L. Barnard, 1972b: 109, figs 55–56 (New Zealand) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).– Ledoyer, 1979: 77, fig. 44 [= Zygomaera pseudemarginata (Ledoyer, 1982) (Madagascar)].–Lowry & Fenwick, 1983: 236 (New Zealand subantarctic) (=? L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).

Not Maera mastersii .–Chevreux, 1908: 481 (French Polynesia).– Stebbing, 1910b: 457 (South Africa).–Chilton, 1916: 367 (New Zealand).–Chilton, 1925: 317 (Chatham Islands, New Zealand).– Hale, 1929: 215, fig. 213 (figure = L. thomsoni of Miers, 1884) (South Australia) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).–Hurley, 1954: 603 (New Zealand) (= L. tias Krapp-Schickel, 2003 , according to Krapp-Schickel, 2003).– Griffiths, 1974b:291 (SouthAfrica).–J.L.Barnard,1962: 99 (key).

Type material. Syntype, female, ovigerous, AM P3487 , Port Jackson, New South Wales , Australia , [approx. 33°50.9'S 151°16.2'E], [from AM Old Collection].

Additional material examined. New South Wales: male, 11.8 mm, AM P60389; female, 12.5 mm, AM P27286, Bottle and Glass Rocks, Port Jackson, 33°50.9'S 151°16.2'E, in and among dense tubes on sediment covered rocks, G.D. Fenwick, 29 Aug 1977. 1♂, AM P60390; 5 specimens, AM P60391, off Wy-ar-gine Point, Port Jackson, [approx. 33°49'S 151°15.1'E], sand and shell, dredge, Malacological Society, 8 May 1971. 1 specimen, AM P60392, northeast of Marys Rock, Cook Island, 28°11.42'S 153°34.79'E, orange bryozoan, 19 m, R.T. Springthorpe, 8 June 1993, stn NSW-816.

Type locality. Port Jackson, New South Wales, Australia, [approx. 33°50.9'S 151°16.2'E].

Description. Based on syntype female, AM P3487, male, AM P60389 and female AM P27286.

Head. Lateral cephalic lobes broad, rounded, with anteroventral slit, anteroventral corner subquadrate, with acute/subacute spine. Antenna 1 longer than antenna 2; peduncular article 1 subequal in length to article 2, with 1 distal robust seta on posterior margin; flagellum with 34 articles; accessory flagellum with 6 articles. Antenna 2 peduncular article 2 cone gland reaching at least to end of peduncular article 3; article 4 longer or subequal to article 5; flagellum with 20 articles Mandible palp article 3 rectolinear, setose along straight medial margin, longer than article 1; article 2 longer than article 3; article 1 not produced, shorter than article 2, about twice as long as broad. Maxilla 1 inner plate with about 3 setae mainly terminal.

Pereon. Gnathopod 1 coxa anteroventral corner produced, acute, posteroventral corner notch absent; merus without posterodistal spine; palm extremely acute, slightly convex, without posterodistal corner, defined by posterodistal robust setae. Gnathopod 2 not sexually dimorphic; subchelate; coxa posteroventral corner notch absent; merus with sharp posteroventral spine; carpus compressed; propodus without medial depression, palm acute, straight, sculptured, with sparse robust setae, defined by posterodistal robust setae, defined by posteroventral corner; apically acute/subacute. Pereopod 5 basis posterior margin straight, posteroventral corner broadly rounded. Pereopod 6–7 basis posterior margin convex, posteroventral corner broadly rounded.

Pleon. Epimeron 1 posteroventral corner broadly rounded, or with small acute spine. Epimera 1–2 posteroventral margin without spines above posteroventral corner. Epimeron 3 posterior margin smooth, posteroventral corner with small acute spine. Uropod 3 inner ramus subequal in length to outer ramus; outer ramus longer (1.2 to 2× length) than peduncle, 1-articulate. Telson with robust setae on inner margins (1 or 2 per lobe), without apical robust setae, apical conical extension absent.

Habitat. Marine; littoral; in and among dense tubes on sediment covered rocks, bryozoans, sand and shell, 7 to 19 m depth.

Remarks. Although there are many records of A. mastersii in the literature from inside and outside Australia, only Haswell (1879a: 265, pl. 11, fig. 1), Sheard (1936: 177, fig. 3), J.L. Barnard (1972a: 226, fig. 132), J.L. Barnard, 1972b: 109, figs 55–56 and Ledoyer (1979: 77, fig. 44) illustrated their material. Neither Sheard (1936), nor J.L. Barnard (1972a,b) showed the distinctive third uropods and telson illustrated by Haswell (1879a). Their misidentified species have recently been studied by Krapp-Schickel (2003). The material of Ledoyer (1979) was later shown to be a different species, now known as Zygomaera pseudemarginata (Ledoyer, 1982) . Based on currently available information, A. mastersii appears to be confined to southeastern and possibly southern Australia. Other records attributed to this species (at least since Haswell [1885] synonymized L. thomsoni with A. mastersii and certainly since the illustrations of Sheard [1936]) represent Linguimaera leo and L. tias of Krapp-Schickel (2003) plus several unknown species.

Distribution. New South Wales: Bottle and Glass Rocks and Wy-ar-gine Point, Port Jackson; Marys Rock, Cook Island (all AM).

Australian geographic areas. Southeastern Australia.

Figures

Fig. 55. Dulichiella pacifica n.sp., holotype, male “a”, 4.4 mm, AM P61112, Tandai Point, Guadalcanal, Solomon Islands. Scales for MDp, MX1IP represent 0.1 mm, remainder represent 0.2 mm.

Fig. 56. Dulichiella pacifica n.sp., holotype, male “a”, 4.4 mm, AM P61112, paratype, female, 5.9 mm, AM P61113, Tandai Point, Guadalcanal, Solomon Islands. Scales represent 0.2 mm.