Podocerus talegus lawai J. L. Barnard, 1970

Hughes, L. E., 2013, Podoceridae of Tropical Australia (Peracarida: Amphipoda), Records of the Australian Museum 65 (1), pp. 1-37 : 26-28

Podocerus talegus lawai J. L. Barnard, 1970

Figs 20–21

Podocerus talegus lawai J. L. Barnard, 1970: 241–243 , Figs160, 161.— Myers, 1990: 149–157.

Type locality. Off Ewa Beach, Oahu , Hawaii .

Material examined. Male , 3.8 mm, dissected, 2 slides, AM P.87620, bommies, north west end, McCluer Island (11°02'S 132°58'E), 8 m, branching brown algae, 16 October 1982, coll. G. C. B. Poore (NT 32); 10 specimens, AM P.78306, bommies, north west end, McCluer Island (11°02'S 132°58'E), 8 m, branching brown algae, 16 October 1982, coll. G. C. B. Poore (NT 32); female, 3.2 mm, dissected, 1 slide, AM P.87621, bommies, north west end, McCluer Island (11°02'S 132°58'E), 8 m, branching brown algae, 16 October 1982, coll. G. C. B. Poore (NT 32); male, SEM pin mount, 3.3 mm, AM P.85668, bommies, north west end, McCluer Island (11°02'S 132°58'E), 8 m, branching brown algae, 16 October 1982, coll. G. C. B. Poore (NT 32); 7 specimens, AM P.78305, reef, north side of New Year Island (10°54'S 133°02'E), 2 m, red algae, 13 October 1982, coll. G. C. B. Poore, (NT 1); many specimens, AM P.78312, south end, McCluer Island (11°06'S 133°00'E), 8 m, coral base Acropora sp., 17 October 1982, coll. P. Horner, (NT 59); 3 specimens, AM P.78310 south end, McCluer Island, (11°06'S 133°00'E), 8 m, red algae, 17 October 1982 coll. J. K. Lowry (NT 58) .

Diagnosis. Body cuticle dorsally and laterally smooth with sparse slender setae. Gnathopod 2 carpus indistinct, fused with propodus; propodus palm with one rectangular and one subtriangular tooth, palm poorly defined without corner, tooth or robust setae; dactylus eXtending length of propodus.

Description. Based on male, 3.8 mm. AM P.87620. Body cuticle dorsally and laterally smooth with sparse slender setae. Head dorsally smooth; rostrum short, one tenth of head length; eyes greatly bulging; lateral cephalic lobe subquadrate; anteroventral corner subquadrate. Mandible accessory setal row with 3 robust setae. Maxilla 1 palp distal margin with 5 robust setae.

Gnathopod 1 coxa subequal to coxa 2, as broad as long, anteroventral corner produced anteriorly, apically subacute; basis 3 times as long as broad, basis with a few long slender anterodistal setae; carpus rectolinear, twice as long as broad; propodus subtriangular, anterior margin with clusters of long slender setae, propodus palm margin minutely crenulate, with 1 robust seta near corner of palm; dactylus posterior margin with serrate teeth. Gnathopod 2 basis twice long as broad, anterodistal corner lobe subacute with a few long slender setae; merus posterior margin with rows of slender setae, with narrow produced lobe, lobe as long as broad, apically acute, without robust setae; carpus indistinct, fused with propodus; propodus elongate subovoid, length twice width, anterior margin with clusters of short slender setae, medial surface with dense plumose setae, palm acute, convex, with broad, well developed distal shelf, shelf margin smooth, palm with one rectangular and one subtriangular tooth, palm poorly defined without corner, tooth or robust setae; dactylus eXtending length of propodus.

Epimera 1–3 posteroventral corner rounded. Urosomite 1 length 1.2 times as long as broad. Uropod 1 biramus; peduncle 3 times as long as broad with well-developed ventromedial spine, spine 4 times as long as broad; inner ramus 1.8 times peduncule length; outer ramus about 3⁄4 the length of the inner ramus. Uropod 2 biramous; peduncle ventromedial spine absent; outer ramus about half the length of inner ramus. Uropod 3 uniramus; ramus with 3 apical setae. Telson dorsal lobe with 2 apical setae, lower margin without apical and lateral setae.

Remarks. This report of P. talegus lawai in the Northern Territory is a significant range eXtension, with its original description from Hawaii (J. L. Barnard, 1970) and subsequent report from Tonga ( Myers, 1990). Despite the large geographic distance there is little morphological variation in the material reported. The male gnathopod 2 propodus teeth are more developed and the dactylus more stout in the material figured from the Northern Territory in comparison to other locations, however these features are associated with growth stages.

The male gnathopod 2 propodus palm acute and elongate dactylus define P. talegus lawai , P. gloriosae Ledoyer, 1986 , P. madagascarensis Ledoyer, 1986 and P. orontes sp. nov. Both P. talegus lawai and P. madagascarensis have two teeth along the palm separating it from this species group. The shape of the gnathopod 1 coxa best distinguishes, P. talegus lawai where the anterior corner is not produced while well produced in P. madagascarensis .

Distribution. Australia. Northern Territory, McCluer Island, New Year Island (current study). Hawaii. Oahu (J. L. Barnard, 1970). Tonga ( Myers, 1990).

Figures

Figure 20. Podocerus talegus lawai Barnard, 1970, male, 3.3 mm, AM P.85668, McCluer Island, Northern Territory. SEM photographs: (A) whole animal lateral view (scale 200 µm); (B) whole animal dorsal view (scale 200 µm); (C) gnathopod 2 propodus palm plumose setae (scale 20 µm); (D) head dorsal view (scale 100 µm) and (E) head lateral view (scale 100 µm).

Figure 21. Podocerus talegus lawai Barnard, 1970, male, 3.8 mm, AM P.87620, McCluer Island, Northern Territory, scale 0.1 mm.