Ceradocus cf. rubromaculatus ( Stimpson, 1856 )

Krapp-Schickel, Traudl, 2009, Maeridae, the Ceradocus group *, Zootaxa 2260 (1), pp. 598-642 : 607-610

Ceradocus cf. rubromaculatus ( Stimpson, 1856)

( Figs 7 , 8 )

? Ceradocus rubromaculatus . –K.H. Barnard, 1931: 124.

Material examined. 1 female?, 6.0 mm, AM P77698 ( JDT / OPH 2 ) .

Type locality: Sydney , Australia (~ 33°51'S 151°15'E) .

Description. Based on female?, 6.0 mm, AM P77698.

Head. Head, subocular notch present. Antenna 1 peduncular article 2 subequal with article 1; accessory flagellum with 4 articles. Mandible palp article 1 distally asymmetrically lengthened; article 3 about half length of article 2.

Pereon. Gnathopod 1 propodus and carpus subequal. Gnathopod 2 asymmetrical, large gnathopod palm regularly rounded without corner, propodus length twice the width; small gnathopod palm also regularly rounded without corner, propodus length 2.4 x width. In large palm excavation present near dactylus insertion, broad hump molar-like. Pereopod 7 basis posterior margin smooth, length 2 x width.

Pleon. Pleonite 1 with small mediodorsal spine, pleonite 2 with 1 small medial spine and several tiny lateral ones. Epimeron 1 posterior margin dorsally serrated, posteroventral and ventral margins smooth. Epimeron 2 posterior margin dorsally serrated, posteroventral margin smooth, ventral margin with tiny incisions. Epimeron 3 dorsally serrated, posteroventral and ventral margins serrated. Uropod 3 missing. Telson lateral plumose setae present, one subdistal robust seta, scarcely exceeding tip of telsonic lobe.

Male (sexually dimorphic characters). Unknown.

Habitat. Coral rubble, 2 m.

Remarks. Most of the known Ceradocus species show a well pronounced palmar corner on gnathopod 2, not only in males but also in females. There are only 7 species with oval gnathopod 2 propodus in females: four of them have other clear morphological differences: C. serratus ( Bate, 1862) from England, but also reported from Australia (doubtfully the same species), has a smooth ventral and serrated posteroventral margin in epimeron 2; C. spinifera Ledoyer, 1973 from Madagascar has a serrated posteroventral margin on epimeron 1 and serrations on posterior and ventral margin of epimeron 2; in C. woorree Berents, 1983 , the dentation on the body is lacking; in C. yandala Berents, 1983 , from Australia the second gnathopods have a nearly right-angled palmar corner with a U-shaped incision in the middle of the palm.

In C. greeni Appadoo & Myers, 2005 from Mauritius, C. inermis Hirayama, 1986 from Ariake Sea and C. rubromaculatus ( Stimpson, 1856) from Australia, there are dentations also on the urosomites which do not occur in the present specimen. The shape of the gnathopods is closest to that of C. rubromaculatus , hence the tentative placement of the single female here.

Distribution. Australia. Orpheus Island (current study);? Low Isles (K.H. Barnard, 1931).

Figures

FIGURE 7. Ceradocus cf. rubromaculatus (Stimpson, 1856), adult, sex unknown, 6.0 mm, AM P77698, Cobble Beach, Orpheus Island, Great Barrier Reef.

FIGURE 8. Ceradocus cf. rubromaculatus (Stimpson, 1856), adult, sex unknown, 6.0 mm, AM P77698, Cobble Beach, Orpheus Island, Great Barrier Reef.