Podocerus crenulatus Myers, 1985

Kilgallen, Niamh M., 2009, Podoceridae *, Zootaxa 2260 (1), pp. 841-860 : 850-853

Podocerus crenulatus Myers, 1985

( Figs 6 , 7 )

Podocerus crenulatus Myers, 1985: 60 , fig. 44.

Material examined. 1 female, AM P76898 and 1 female, AM P76899 ( QLD 27 ) ; 3 females, AM P77406 ( QLD 28 ) ; 1 female, AM P77407 ( QLD 45 ) ; holotype, male, AM P35190; paratypes , 2 males, 2 females, AM P35191 .

Type locality. Momi Bay , Viti Levu, Fiji.

Description. Based on female, 2 mm, AM P76898 (QLD 27).

Head. Antenna 2 well developed, slender, slightly longer than body, without dense concentration of long slender setae along posterior margin, article 5 about 1.5 x longer than article 4; flagellum 4-articulate. Mandible palp 3-articulate; molar well developed; right mandible incisor with 5 teeth, lacinia mobilis with 2 teeth, accessory setal row with 2 setae; left incisor with 5 teeth, lacinia mobilis with 4 teeth, accessory setal row with 3 setae. Maxilliped outer plate well developed; palp article 2 scarcely setose on inner margin; article 3 with few distal setae; article 4 reduced, blunt.

Pereon. Pereonites not fused; pereonites 2–6 with gills; pereonites 3–7 produced posterodorsally, and with few fine dorsal setae. Gnathopod 1 propodus subtriangular; palm acute, minutely serrate, beginning about one-third along posterior margin of propodus; dactylus with 2 accessory teeth, inner margin minutely serrate. Gnathopod 2 coxa reduced; basis without anterodistal projection; merus not acutely projecting distally; propodus large, subovate, anterodistal margin convex; palm smooth, convex, and without projections. Pereopods 3 –7 missing from all specimens collected.

Pleon. P leonites not fused; pleonites 1–2 produced posterodorsally, and with few fine dorsal setae. Uropod 1 peduncle without distoventral spine; rami longer than peduncle, inner ramus longer than outer ramus, with few marginal robust setae. Uropod 2 peduncle without distoventral spine; outer ramus about subequal in length to peduncle, inner ramus much longer. Uropod 3 present, uni-articulate. Telson apically rounded or subacute, with 2 apical setae.

Habitat. Found on algae and sediment from sea grass.

Remarks. Myers (1985) gives a comprehensive comparison between Podocerus crenulatus and several of its congeners, however, he does not remark on the similarity between it and P. lobatus ( Haswell, 1885) . The lack of detail in Haswell’s (1885) original description and illustrations of this latter species makes an accurate comparison difficult; however, it appears that there are definite similarities. The antennae, in particular, correspond almost exactly to those of P. crenulatus . There are, nonetheless, a few noteworthy differences. Firstly, the production of the gnathopod 2 merus is different between the two species, being acute and pointed in P. lobatus , but more rounded in P. crenulatus . Also, Haswell does not mention any posterodorsal production of the posterior segments of the pereon and the pleon, while he does note a rounded elevation of the anterior four pereonites which are not present on P. crenulatus . The type material of P. lobatus is lost and it has not been recorded since (the record of Pirlot (1938) is considered erroneous), thus making comparison of specimens impossible. However, given the subtlety of character states in distinguishing members of this genus, and the apparent slight differences between the material examined here and that described by Haswell (1885), it is likely that these are indeed two distinct species.

Distribution. Australia. Queensland: Lizard Island (current study). Fiji. Viti Levu: Momi Bay ( Myers 1985).

Figures

FIGURE 6. Podocerus crenulatus Myers, 1985, female, 2 mm, AM P76898, Fringing reef between Bird Islet and South Island, Lizard Island, Great Barrier Reef.

FIGURE 7. Podocerus crenulatus Myers, 1985, female 2 mm, AM P76898, Fringing reef between Bird Islet and South Island, Lizard Island, Great Barrier Reef.