Melita myersi G. Karaman, 1987

Lowry, J. K. & Springthorpe, R. T., 2009, Melitidae, the Melita group *, Zootaxa 2260 (1), pp. 718-735 : 723-726

Melita myersi G. Karaman, 1987

( Figs 4 , 5 )

Melita zeylanica . –– Myers, 1985: 125, figs 98–99.

Melita myersi G. Karaman, 1987: 30 .

Material examined. 1 specimen, AM P55298 ( QLD 36 ) ; 1 male, 4.4 mm, AM P55295 ( QLD 42 ) ; 1 female 3.9 mm, AM P55296 ( QLD 42 ) ; 2 specimens, AM P55297 ( QLD 42 ) ; 4 specimens, AM P77779 ( SEL /LZI-1- 1) ; 1 male, AM P47332, ( NCL 140 ) .

Type locality. Mangroves , Lucala Island, Fiji (~ 18°10'S 178°30'E) .

Description. Based on male, 4.4 mm, AM P55295.

Head. Head lateral cephalic lobe broad, apically rounded; eyes well developed, ovate; anteroventral margin without notch or slit, slightly recessed, anteroventral corner rounded. Antenna 1 longer than antenna 2; peduncular article 1 shorter than article 2, with 3 robust setae along posterior margin; peduncular article 2 longer than article 3; accessory flagellum minute with 2 articles; flagellum with 11 articles. Antenna 2 not strongly setose; peduncular article 4 subequal to article 5; flagellum with 6 articles. Mandible molar medium size; accessory setal row well developed; palp well developed, 3-articulate; article 1 about as long as broad, not produced distally; article 2 longer than article 3; article 3 well developed, slightly tapering distally, with setae mostly terminal. Maxilla 1 inner plate long, subrectangular, with mainly apical setae. Maxilla 2 inner plate without oblique setal row on inner face, without marginal setal row. Lower lip inner lobes vestigial or absent. Maxilliped palp article 3, about as long as broad.

Pereon. Gnathopod 1 sexually dimorphic; coxa anteroventral corner not produced, anterior margin straight; merus without posterodistal tooth; carpus about 2 x as long as broad, longer (1.3x) than propodus; propodus without hump along anterior margin, anterodistal projection forming rounded hood over dactylus, palm obtuse, convex, entire, without narrow anterodistal projection near base of dactylus, posterodistal margin not swollen, palm defined by posterodistal corner, corner with posterodistal robust setae; dactylus articulating distinctly with propodus, fitting palm, posterior margin swollen at base. Gnathopod 2 significantly enlarged in male, not in female; sexually dimorphic (size, not shape); subchelate; carpus short, length 1.1 x breadth, not lobate, not enclosed by merus and propodus; merus with subquadrate distoventral corner; propodus without strong concentration of setae, without medial depression, without medial pad, palm acute in male and female, with well defined corner, slightly convex, lined with robust setae, without posteroventral corner, without posterodistal robust setae; dactylus closing along palm, with 1 or 2 setae on anterior margin. Pereopods 5–6 basis posterior margin minutely castellate. Pereopod 4 coxa posteroventral lobe absent, posterior margin concave. Pereopod 5 basis proximally expanded, tapering distally; posterior margin convex, posteroventral corner broadly rounded; carpus and propodus with few (or none) long, slender setae along anterior margin. Pereopod 6 coxa slightly produced, rounded; basis convex, posteroventral corner broadly rounded. Pereopod 7 basis posterior margin convex, with posterior margin minutely castelloserrate, evenly rounded posteriorly, produced posterodistally (lobate), posterodistal corner broadly rounded.

Pleon. Pleonites 1–3 without dorsal spines or setae. Urosomites 1–3 without dorsal spines. Epimeron 1 anteroventral corner rounded, posteroventral corner with small acute or subacute spine. Epimeron 2 posteroventral corner acute. Epimeron 3 ventral margin smooth, posteroventral corner with strongly produced acute spine, posteroventral margin smooth. Urosomite 2 with 2 groups of 2 small dorsolateral robust setae. Urosomite 3 without dorsal setae. Uropod 1 peduncle with basofacial robust seta. Uropod 3 rami distally truncated; inner ramus scale-like, much shorter than outer ramus; outer ramus very long, length 5 x breadth, much longer (about 2.5 x) than peduncle, 1-articulate. Telson cleft, as long as broad, lobes apically acute, without dorsal robust setae, each lobe with 3 apical/subapical long, robust setae, apical/subapical with robust setae on inner margins, absent on outer margins.

Female (sexually dimorphic characters). Based on a female, 3.9 mm, AM P55296. Gnathopod 1 propodus without anterodistal hood. Gnathopod 2 carpus long, length 1.5 x breadth; propodus palm smooth. Pereopod 6 coxa anterior lobe ventral margin strongly produced, curved posteriorly and rounded.

Habitat. Marine or estuarine among mangroves.

Remarks. Karaman (1987) recognized that Myers (1985) had actually described a new species which he mistakenly called M. zeylanica Stebbing, 1904 and assigned the new name, M. myersi , to the taxon.

The mouthparts of M. myersi are illustrated here for the first time. We examined a number of specimens from Fiji and found a range of articles (11 to 23) on the flagellum of antenna 2. The original illustration ( Myers 1985) of the anterodistal hood on the propodus of the male gnathopod 1 is not convincing unless the medial suture is not drawn. However Myers (1985) states that his specimens have the aberrant 'melitoid' gnathopod 1 of M. zeylanica . Urosomite 2 has 4 small robust setae in two bundles, not 3 as indicated in Myers (1985).

Based on this evidence we are reporting specimens of this species from the same and similar habitats in New Caledonia and at Lizard Island in north-eastern Australia.

Melita myersi appears to be most similar to Melita laevidorsum Stephensen, 1944 from Japan. Both species have the anterodistal hood on the propodus of male gnathopod 1, the dactylus of male gnathopod 2 closing along the palm and the coxa of pereopod 4 without a posterodistal lobe. Melita laevidorsum differs from M. myersi in having a better developed accessory flagellum and less expanded bases on pereopod 5–7.

Distribution. Australia. Lizard Island (current study). Fiji. Suva and Lucala Island ( Myers 1985). New Caledonia. Poé Plage (current study).

Figures

FIGURE 4. Melita myersi Karaman, 1987, male, 4.4 mm, AM P55295, Mangrove Beach, Lizard Island, Great Barrier Reef.

FIGURE 5. Melita myersi Karaman, 1987, male, 4.4 mm, AM P55295, female, 3.9 mm, AM P55296, Mangrove Beach, Lizard Island, Great Barrier Reef.