Quadrimaera quadrimana ( Dana, 1853 )

Krapp-Schickel, Traudl, 2009, Maeridae, the Ceradocus group *, Zootaxa 2260 (1), pp. 598-642 : 629-630

Quadrimaera quadrimana ( Dana, 1853)

( Fig. 21 )

Gammarus quadrimanus Dana, 1853: 955 , pl. 65, fig. 9.

Maera quadrimana . — Schellenberg, 1938: 45, figs 21–22. —J.L. Barnard, 1965: 511, fig. 17. —J.L. Barnard, 1970: 152, figs 94–95. — Ledoyer, 1972: 229, pl. 45. — Berents, 1983: 128, fig. 22. — Myers, 1985: 116, fig. 91.

Quadrimaera quadrimana . — Lowry & Stoddart, 2003: 186.

Material examined. 1 female "intersex", 3.5 mm (slide), AM P77724 ( JDT / LIZ 2 ) ; 1 male, AM P77726 ( JDT / LIZ 3 ) ; 1 male, AM P77725 ( JDT / OPH 2 ) ; 1 female, 5 juveniles, AM P70601 ( QLD 1622 ) ; 1 female incomplete, AM P70963 ( QLD 1687 ) ; 1 female incomplete, AM P71030 ( QLD 1711 ) ; 1 male, 5.0 mm (2 slides), AM P71041 ( QLD 1715 ) ; 2 males, 9 females, AM P71270 ( QLD 1767 ) ; 1 female, AM P71280 ( QLD 1770 ) ; 1 male, 1 female, AM P71474 ( QLD 1792 ) ; 1 male, 8 females, AM P77727 ( SEL /LZI-2-7) .

Type locality. Fiji (~ 17°40'S 178°31'E) .

Description. Based on male, 5.0 mm, AM P71041.

Head. Head anteroventral corner produced into a sharp cusp, lacking anteroventral slit. Antenna 1 peduncular article 2 longer than article 1; accessory flagellum with 5–6 articles. Antenna 2 gland cone reaching end of short article 3. Mandible palp article 3 longer than article 2.

Pereon. Gnathopod 1 coxa quadrangular, anteroventral corner rounded; carpus triangular, with notch on anterodistal margin; propodus ovoid. Gnathopod 2 propodus rectangular with parallel margins, palm defined by V-shaped incision next to prominent acute spine; medially two smaller narrow incisions defining two molar-shaped elevations; dactylus outer margin with 1 seta, inner margin smooth. Pereopods 3–7 with bifid dactylus. Pereopods 5–7 basis narrow with sub-parallel margins and a posteroventral corner. Pereopod 7 propodus posterior margin with one group of long setae.

Pleon. Epimera smooth. Uropod 3 rami subequal, longer than peduncle, outer ramus somewhat longer, truncate and with many robust setae that are shorter than ramus. Telson deeply cleft, lobes distally evenly truncate and with 4 robust setae, some longer, some shorter than telson length.

Female (sexually dimorphic characters). Based on female, 3.5 mm, AM P77724. Gnathopod 2 propodus palm with regularly serrate palm.

Variation. Ovigerous females may have regularly serrate palmar margin or in larger individuals, a palm similar to that of males with two deeper incisions (see also Schellenberg 1938 and Myers 1985).

Habitat. Tunicates, coral rubble, mixed coralline algae with epiphytes, brown algal tufts, bommies and sand patches, seagrass, 1–17 m depth.

Remarks. This species is found in the same group with Q. pacifica (see description above). Many authors described problems with highly variable material: juveniles have very narrow rectangular pereopod bases with ratio of length to width of about 2 (see Schellenberg, 1938: 47 fig. 22), while a male of 6.4 mm is described by J.L. Barnard (1970:153 fig. 94) with a pereopod 7 basis ratio of length to width of 1.4. J.L. Barnard (1965: 511 fig. 17) shows that the middle spine on the palmar margin can be worn.

Distribution. Australia. Queensland, Lizard Island ( Berents 1983, current study). Madagascar ( Ledoyer 1972, 1983). India ( Sivaprakasam 1968). Marshall Islands and Kiribati ( Schellenberg 1938; J.L. Barnard 1965). Fiji ( Dana 1853, Schellenberg 1938, Myers 1985). Hawaii ( Schellenberg 1938, J.L. Barnard 1970).

Figures

FIGURE 21. Quadrimaera quadrimana (Dana, 1853), male, 5.0 mm, AM P71041, Mermaid Cove, Lizard Island, Great Barrier Reef.