Podocerus talegus talegus J.L. Barnard, 1965

Kilgallen, Niamh M., 2009, Podoceridae *, Zootaxa 2260 (1), pp. 841-860 : 853-856

Podocerus talegus talegus J.L. Barnard, 1965

( Figs 8 , 9 )

Podocerus talegus J.L. Barnard, 1965: 544 , fig. 35.

Podocerus cristatus . — Ledoyer, 1972: 266, fig. 72.

Material examined. 1 male, AM P77416 and 1 female AM P77417 ( QLD 11 ) ; 3 females, 1 male, AM P77418 ( QLD 1977 ) ; 1 female, AM P77419 ( QLD 1961 ) ; 2 females AM P77420 ( QLD 2006 ) ; 2 females, AM P77421 ( QLD 1959 ) ; 1 female, AM P77422 ( QLD 1978 ) ; 1 female, AM P77423 ( QLD 1975 ) ; 3 females, AM P77424 ( QLD 2000 ) ; 1 female, AM P77425 ( QLD 1996 ) ; 3 males, 6 females, AM P77426 ( QLD 1962 ) . 3 females, 1 male, AM P77427 ( QLD 1976 ) ; 2 females, 1 male, AM P77428 ( QLD 1994 ) ; 2 females, AM P77429 ( QLD 1992 ) ; 1 specimen, AM P77430 ( QLD 1995 ) .

Type locality. Ifaluk Atoll , Caroline Islands, Micronesia .

Description. Based on male, 3.5 mm, AM P77416.

Head. Mandible right incisor with 5 teeth; lacinia mobilis with 4 teeth; accessory setal row with 2 setae; molar present, well developed; left incisor with 5 teeth. Maxilliped inner plate quadrilateral, smaller than outer plate; inner margin of outer plate with row of robust setae; 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; pereonite 7 slightly produced posterodorsally, with clumps of dorsal setae. Gnathopod 1 coxa acutely produced anterodistally; propodus subovate, with 3 rows of submarginal setae near anterior margin; posterior margin continuously rounded with undefined palm; dactylus inner margin deeply serrate with 5 teeth. Gnathopod 2 coxa reduced; basis with 2 large anterodistal lobes; merus forming acute, short distal projection; propodus massive, subovate, length 1.25 x width; palm not defined, palm margin irregular, with 2 large midpalmar projections and broad, well developed distal shelf with 5–6 small, rounded lobes. Pereopods 3–4 well developed. Pereopod 5 missing. Pereopod 6 basis subovate, slightly longer than merus; merus subequal in length to carpus; propodus shorter than carpus and merus combined; dactylus about half propodus length. Pereopod 7 similar to pereopod 6.

Pleon. Pleonites not fused; pleonites 1–2 slightly produced posterodorsally, with clumps of dorsal setae. Uropod 1 peduncle with distoventral spine; biramous with inner ramus almost twice as long as outer ramus and slightly longer than peduncle, with marginal row of minute denticles and 4–5 robust setae. Uropod 2 well developed, peduncle lacking distoventral spine, biramous with inner ramus longer than outer ramus. Uropod 3 uni-articulate. Telson posterodorsally produced into subacute knob with 2 apical setae.

Female (sexually dimorphic characters). Based on female, 3 mm, AM P77417. Gnathopod 2 basis with acute distal projection; merus distal projection slight, shorter than in male; propodus subovate, palm defined by 2 robust setae, palm margin convex, smooth, without projections.

Habitat. Among algae, Halimeda sp. and Caulerpa sp.

Remarks. Podocerus talegus talegus is readily distinguished by the ornamentation of the gnathopod 2 palm. It differs from the other subspecies in the group, Podocerus talegus lawai J. L. Barnard, 1970 , and P. talegus levuensis Myers, 1985 , by the evenly-rounded posterior margin of the gnathopod 1 propodus. Additionally, it differs from P. talegus levuensis by the lack of a palm-defining projection on the posterior margin of the gnathopod 2 propodus.

Ledoyer (1972) states that his identification of P. cristatus ( Thomson, 1879) is similar to P. talegus but that the palmar projections of the second gnathopod are much more pronounced in his specimens. Upon examination of specimens collected for this study, however, it was noted that the strength of these projections depends on the maturity of the animal and angle of the appendage on the slide during examination. After comparing illustrations of Ledoyer’s (1972) specimen with that of J.L. Barnard’s (1965), it was concluded that these are, in fact, conspecific, thus, greatly increasing the known distributional range of the subspecies.

Distribution. Australia. Queensland: Lizard Island (current study). Madagascar. Tuléar ( Ledoyer 1972). Micronesia. Caroline Islands: Ifaluk Atoll (J.L. Barnard 1965).

Figures

FIGURE 8. Podocerus talegus talegus J.L. Barnard, 1965, male 3.5 mm, AM P77416, west end of Blue Lagoon, Lizard Island, Great Barrier Reef.

FIGURE 9. Podocerus talegus talegus J.L. Barnard, 1965, male 3.5 mm, female 3 mm, AM P77416, west end of Blue Lagoon, Lizard Island, Great Barrier Reef.