Plumithoe quadrimana ( Haswell, 1879 )

Hughes, L. E. & Lowry, J. K., 2009, Ampithoidae *, Zootaxa 2260 (1), pp. 153-219 : 211-214

Plumithoe quadrimana ( Haswell, 1879)

( Figs 35 , 36 )

Amphithoe quadrimanus Haswell, 1879: 337 , pl. 21, fig. 7. — Springthorpe & Lowry, 1994: 129.

Ampithoe quadrimana . — Stebbing, 1906: 635.

Ampithoe quadrimanus . — Barnard & Karaman, 1991: 103.

Plumithoe quadrimana . — Poore & Lowry, 1997: 932, figs 26–29.

Plumithoe quadrimanus . — Lowry & Stoddart, 2003: 62 (catalogue).

Material examined. 4 unsexed, AM P62559 ( QLD 1335); many unsexed, AM P75878 ( QLD 1952); 1 dissected male ‘C’, 4.1 mm, 3 slides, AM P76986 ( QLD 2006); 1 dissected female ‘D’, 3.5 mm, 3 slides, AM P76987 ( QLD 2006); many unsexed, AM P75877 ( QLD 2006).

Type locality. Shark Bay , Port Jackson, New South Wales, Australia (~ 33°51'12"S 151°15'54"E), living on Colpomenia sp. , 1–2 m.

Description. Based on male, 4.1 mm, AM P76986.

Head. Head about as long as deep. Antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2; flagellum 16 articles; accessory flagellum absent. Antenna 2 peduncle with long, dense plumose setae on ventral margin; article 4 longer than article 5. Upper lip directed nearly straight down, lateral margins each with midlateral notch. Mandible molar well developed, triturating, accessory setal row with 3 serrate setae; palp 3–articulate, apically setose; article 1 shorter than article 2; article 2 subequal in length to article 3, slender setae present. Lower lip outer plates forming a medial slit, lateral lobe distinctly longer than medial lobe; mandibular lobe with curved margins, rounded apically. Maxilla 1 inner plate with 1 seta; palp article 2 broad. Maxilla 2 inner plate narrower than outer plate. Maxilliped outer plate with row of small robust setae along medial margin.

Pereon. Coxae 1–4 deeper than broad, without ventral setae. Gnathopod 1 smaller than gnathopod 2; coxa distinctly larger than coxa 2, anterodistally produced, anterior margin concave, anteroventral corner acute; basis shorter than coxa, anterodistal lobe rounded, without setae; merus posterodistal lobe acute; carpus about 1.5 x as long as broad, shorter than propodus, anterior margin without setae, posterior margin truncated; propodus narrow, subrectangular; palm acute, straight, with posterodistal corner rounded, with 1 robust seta defining palm; dactylus subequal in length to palm, inner margin crenate. Gnathopod 2 basis with sparse medial slender setae, anterodistal lobe small, rounded, anterodistal corner without setae; merus margin with short, subacute distal lobe; carpus much shorter than propodus, subtriangular; propodus broad, less than 1.5 x as long as broad, subrectangular; palm transverse, slightly excavate, with subquadrate posterodistal corner, without robust seta defining palm; dactylus overreaching palm, tapering evenly, apically acute, inner margin serrate.

Pereopods 3–4 basis narrow; merus subequal in length to carpus. Pereopod 5 without medial slender setae, distal articles broad; propodus slightly expanded distally, with anterodistal striated robust setae; dactylus strongly curved. Pereopod 6 distal articles slender; propodus slightly expanded distally; dactylus slightly curved. Pereopod 7 similar to pereopod 6.

Pleon. Epimera 2–3 posteroventral corner narrowly rounded. Uropod 1 peduncle with 3 robust setae, with 4 lateral slender setae, with large, acute distoventral spine; outer ramus with 1 lateral robust seta; inner ramus with 1 lateral robust seta. Uropod 2 peduncle with 2 robust setae, with 3 lateral slender setae; outer ramus with 1 lateral robust seta; inner ramus with 1 lateral robust seta. Uropod 3 peduncle longer than broad, less than 2 x length of rami, marginal slender setae present, with 2 distal peduncular robust setae, with 4 distal slender setae; outer ramus with 3 large recurved distal robust setae, two with apical accessory spines, with 1 lateral robust seta and 1 lateral slender seta, inner ramus with 4 robust and 2 slender distal setae. Telson subtrapezoidal, apically subacute, with small apical cusp on each distolateral corner, with 2 pair of oblique medial slender setae, with 1 pair of lateral setae, 2 pair of lateral and 1 pair of apical plumose setae.

Female (sexually dimorphic characters). Based on female, 3.5 mm, AM P76987. Gnathopod 1 subequal in size to gnathopod 2; dactylus overreaching palm. Gnathopod 2 basis with 2 long, simple setae on posterior margin, anterodistal corner without setae; propodus narrow, greater than 1.5 x as long as broad; palm acute, entire, rounded, with 1 robust seta defining palm; dactylus slightly overreaching palm.

Habitat. Brown algae Turbinaria sp. and green algae Caulerpa sp. , and Halimeda sp. Also on dead coral with epiphytes.

Remarks. These are the first records of P. quadrimana outside of Port Jackson. The species can be distinguished from all other ampithoids on the Great Barrier Reef by its small size and the tuft of dense setae on the antenna 2 peduncle, characteristic of Plumithoe .

Distribution. Australia. Queensland: Heron Island; One Tree Island (current study). New South Wales: Port Jackson ( Haswell 1879; Poore & Lowry 1997).

Figures

FIGURE 35. Plumithoe quadrimana (Haswell, 1879), male ‘c’, 4.1 mm, AM P76986, Heron Island, Great Barrier Reef.

FIGURE 36. Plumithoe quadrimana (Haswell, 1879), male, 4.1 mm, AM P76986, female ‘D’, 3.5 mm, AM P76987 Heron Island, Great Barrier Reef.