Ampithoe cookana Peart, 2007

Hughes, L. E. & Lowry, J. K., 2009, Ampithoidae *, Zootaxa 2260 (1), pp. 153-219 : 154-157

Ampithoe cookana Peart, 2007

( Figs 1 , 2 )

Ampithoe cookana Peart, 2007b: 13 , figs. 7–10 (key).

Material examined. 3 unsexed, AM P76242 (1974) ; 1 unsexed, AM P76244 ( QLD 1975 ) ; 6 unsexed, AM P76243 ( QLD 1978 ) ; 6 unsexed, AM P76241 ( QLD 1999 ) ; 1 male ‘ A’ dissected, 7.0 mm, 3 slides, AM P76240 ( QLD 2000 ) ; 1 dissected male ‘B’, 7.2 mm, 3 slides, AM P76239 ( QLD 2000 ) ; 1 female dissected, 6.5 mm, 3 slides, AM P76238 ( QLD 2000 ) .

Type locality. North ledge, Cook Island , New South Wales (28º11.44’S 153º34.67’E), living in Chlorodesmis sp. , 12 m.

Description. Based on ‘B’ male, 7.2 mm, AM P76239.

Head. Head as long as deep. Antennae 1–2 missing [in female paratype antenna 1 longer than antenna 2; peduncular article 1 subequal to article 2 with 4 robust setae along posterior margin; flagellum 29 articles; accessory flagellum absent. Antenna 2 peduncle with dense setose clumps on articles 3 to 5; article 4 subequal in length to article 5; flagellum 6+ articles]. Mandible molar well developed, triturating, accessory setal row with 5 serrate robust setae; palp 3–articulate, marginally setose; article 1 shorter than article 2, slender setae present; article 2 subequal in length to article 3. Lower lip outer plates notched, forming a medial excavation, lateral lobe distinctly longer than medial lobe; mandibular lobe with curved margins, rounded apically. Maxilla 1 inner plate with more than 4 slender setae; palp article 2 slender. Maxilliped outer plate with row of large robust setae along medial margin.

Pereon. Coxae 1–4 deeper than broad. Gnathopod 1 smaller than gnathopod 2; coxa subequal to coxa 2, anteroventrally produced, anterior margin straight, anteroventral corner narrowly rounded; basis shorter than coxa, anterodistal lobe rounded, with 1 slender seta; merus posterodistal lobe acute; carpus about 1.5 x as long as broad, shorter than propodus, anterior margin with 1 robust seta, posterior margin straight; propodus narrow, subrectangular; palm transverse acute, convex, with rounded posterodistal corner, with 1 robust seta defining palm; dactylus slightly overreaching palm, inner margin crenate. Gnathopod 2 coxa without long, plumose setal fringe on ventral margin, basis with medial fringe of long, slender setae, anterodistal corner with 4 robust setae; merus margin without lobe; carpus shorter than propodus, subtriangular, with 7 robust setae along anterior margin; propodus broad, less than 1.5 x as long as broad, subrectangular, not produced into an anterodistally setose lobe; palm acute, excavate, with posterodistal tooth of medium length (length 2 x breadth), apically subacute, without palm defining robust seta; dactylus equal in length to palm, tapering evenly, apically acute, inner margin crenate. Pereopods 3–4 basis slightly expanded; merus longer than carpus. Pereopods 5–7 simple. Pereopod 6 basis posterior margin sinusoidal, with several marginal robust setae; distal articles slender; propodus not expanded distally, with 2 anterodistal striated robust setae; dactylus slightly curved.

Pleon. Epimera 2–3 posteroventral corner broadly rounded. Uropod 1 peduncle with more than 13 robust setae, with short fringe of slender setae (less than 0.5 x length of peduncle), distoventral spine absent; rami subequal in length; outer ramus slender, length about 5–6 x as long as broad, with 9 marginal robust setae. Uropod 2 peduncle with 2 robust setae; outer ramus with 8 lateral robust setae; inner ramus with 9 lateral robust setae. Uropod 3 peduncle longer than broad, more than 2 x length of rami, without marginal slender setae, with 5 distal robust setae, with 5 distal slender setae; outer ramus with 2 large recurved distal robust setae, without lateral robust or slender setae; inner ramus with 6 distal slender setae, without lateral robust setae. Telson subtriangular, apically rounded, with small apical cusp on each distolateral corner, with 3 pair of lateral and1 pair of apical slender setae, and with 2 pair of lateral and 1 pair of apical plumose setae.

Female (sexually dimorphic characters). Based on female, 6.5 mm, AM P76238. Gnathopod 1 subequal in size to gnathopod 2; coxa anterior margin slightly concave, anteroventral corner rounded; basis with 3 slender setae; carpus anterior margin with slender setae; palm subacute, straight. Gnathopod 2 basis anterodistal corner with 2 slender setae; palm entire, with rounded posterodistal corner, with 1 robust seta defining palm.

Habitat. Chlorodesmis sp. , dead Acropora sp. coral with epiphytes.

Remarks. Ampithoe cookana belongs to a group of Ampithoe species with a posterodistal tooth defining the palm of male gnathopod 2. This group includes: A. akuolaka J.L. Barnard, 1970 ; A. katae Peart, 2007b ; A. platycera Sivaprakasam, 1971 , A. rachanoi Peart, 2002 , A. waialua J.L. Barnard, 1970 and the species complex associated with A. ramondi Audouin, 1826 . Ampithoe cookana may be distinguished from these species by the male gnathopod 2 propodus which lacks the anterodistal hood and the gnathopod 1 palm which is convex. Within the GBR Ampithoe cookana is similar to A. katae , however A. katae has an anterodistal hood on gnathopod 2 and is more setose along the anterodistal propodus margin.

Distribution. Australia. New South Wales: Cook Island ( Peart 2007b). Queensland: One Tree Island (current study).

Figures

FIGURE 1. Ampithoe cookana Peart, 2007b, male ‘A’, 7.0 mm, AM P76240, One Tree Island, Great Barrier Reef.

FIGURE 2. Ampithoe cookana Peart, 2007b, male ‘A’, 7.0 mm, AM P76240, female, 6.5 mm, AM P76238, One Tree Island, Great Barrier Reef.