Podocerus brasiliensis
Creators: name: Kilgallen, Niamh M.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Podoceridae
Podocerus
Podocerus brasiliensis

description: Podocerus brasiliensis (Dana, 1853)   
(Figs 1, 2)  
 Platophium brasiliense Dana, 1853: 838, pl. 55, fig. 9.   
 Platophium synaptochair Walker, 1904: 296, pl. 8, fig. 52.   
 Podocerus brasiliensis. — Stebbing, 1906: 704. —K.H. Barnard, 1925: 366. — Schellenberg, 1928: 674. —K.H. Barnard, 1935: 305. — Schellenberg, 1938: 94. —J.L. Barnard, 1953: 87. —J.L. Barnard, 1955: 39. —J.L. Barnard, 1959: 39, pl. 13. — Nayar, 1959: 45, pl. 15 figs 21–26. —? J.L. Barnard, 1962: 66, fig. 30. — Nayar, 1965: 164, figs 17d, e. —J.L. Barnard, 1970: 237, figs 156, 157. —J.L. Barnard, 1971: 117, figs 58B – 60B. — Rabindranath, 1972: 302, fig. 2. — Ortiz & Silva, 1990: 180.   
 Material examined. 1 male, AM P76893 and 1 female, AM P77431 (QLD 1895); 1 female, 3 males, AM P76894 (QLD 1895); 1 male, AM P76895 (QLD 1917); 1 female, 4 males, AM P76896 (QLD 1980); 1 male, AM P76897 (QLD 1983).   
 Type locality. Rio de Janeiro, Brazil.   
 Description. Based on male, 5 mm, AM P76893.   
 Head. Eyes large, protruding. Antenna 1 peduncle article 2 slightly longer than article 3; flagellum with more than 2 articles; accessory flagellum present, 1-articulate. Mandible incisor with 5 teeth, molar well developed. Maxilliped inner plate smaller than outer plate, quadrilateral; outer plate about twice length of inner plate, inner margin with row of robust setae and few fine setae; palp article 2 scarcely setose on inner margin; article 3 with few distal setae; article 4 blunt.   
 Pereon. Pereonites not fused; pereonites 2–6 with gills; pereonites 3–7 each with clump of dorsal setae. Gnathopod 1 propodus triangular, with 5–6 rows of submarginal setae near anterior margin; palm densely setose, beginning about one-quarter way along posterior margin of propodus, delimited by one large and one small robust seta; dactylus fitting palm, inner margin serrate at distal end. Gnathopod 2 coxa reduced; basis lacking anterodistal lobe; merus produced posterodistally; carpus indistinct, almost entirely merged with propodus; propodus elongate, longer than basis; palm poorly defined, with brush of long setae arranged in transverse rows; dactylus reaching slightly beyond half palm length. Pereopods 3 and 4 well developed; basis narrow, cylindrical; dactylus elongate, about half propodus length. Pereopod 5 basis poorly expanded posteriorly, about subequal in length to merus; carpus distinctly longer than merus; propodus about 1.5 x carpus length; dactylus longer than half propodus length. Pereopod 6 basis shorter than carpus, slightly longer than merus; propodus shorter than carpus and merus combined; dactylus about half propodus length. Pereopod 7 basis about subequal in length to carpus, and longer than merus; propodus shorter than carpus and merus combined; dactylus slightly shorter than half propodus length.   
 Pleon. Pleonites not fused; pleonite 1 with clump of dorsal setae. Uropod 1 peduncle with distoventral spine; biramous with inner ramus subequal in length to peduncle, with moderately dense marginal row of robust setae and fine denticles on inner margins. Uropod 2 peduncle with distoventral spine; biramous, both inner and outer rami much longer than peduncle. Uropod 3 uni-articulate. Telson apically rounded, posterodorsally produced into subacute knob with 4–8 apical setae.   
 Female (sexually dimorphic characters). Based on female, 3.8 mm, AM P77431. Gnathopod 2 merus with rounded distal projection; carpus distinct; propodus large, subovate; palm smooth, slightly convex, not heavily setose; dactylus fitting palm.   
 Habitat. Associated with turfing brown algae and Padina sp., tufts of red algae and Halimeda sp., 2– 18 m. Often found as a fouling organism on pilings and the hull of ships.   
 Remarks. This species is considered to have a circum-tropical distribution, having previously been recorded from Brazil to California, Hawaii, India, Sri Lanka and Mozambique. Although there does appear to be some slight morphological variation between different populations, the specimens recorded here correspond well with those described by J.L. Barnard (1970, 1971) from Hawaii, and Rabindranath (1972) from India. The only difference noted is the number of projections on the male gnathopod 2 palm — the Indian specimens have two blunt distal projections and the Hawaiian specimens have just one. The specimens examined from the GBR do not appear to have any projections on the gnathopod 2 palm.   
The heavily setose palm and the elongate propodus of the male second gnathopod is a highly distinctive character of this species. Other notable characters include the ventromedial spines on the peduncle of uropods 1 and 2, and the numerous robust apical setae on the telson.  
 Podocerus brasiliensis is a fouling organism (J.L. Barnard 1971), which may explain its wide distribution. The specimen on which this description is based was collected from brown algae on the hull a ship.   
 Distribution. Australia. Queensland: One Tree Island and Thursday Island, (current study). Brazil. Rio de Janeiro (Dana 1853). India. Quilon, Kerala; Gulf of Manaar (Rabindranath 1972). Mozambique. Maputo Bay (Ortiz & Silva 1990). Sri Lanka. Galle Harbour and Galle Bay; Kondatchi Paar; Periya Paar Kerrai; East Cheval Paar (Walker 1904). USA. Pearl Harbour, Hawaii (J.L. Barnard 1971).
description: Published as part of Kilgallen, Niamh M., 2009, Podoceridae *, pp. 841-860 in Zootaxa 2260 (1) on pages 842-844, DOI: 10.11646/zootaxa.2260.1.47, http://zenodo.org/record/5306797