Synidotea karumba, Poore, 2012

Poore, Gary C. B., 2012, Four new valviferan isopods from diverse tropical Australian habitats (Crustacea: Isopoda: Holognathidae and Idoteidae), Memoirs of Museum Victoria 69, pp. 327-340 : 336

Synidotea karumba sp. nov.

Figures 8–10

Material examined. Holotype. Queensland, Karumba, Norman River mouth (17°28'S, 140°49'E), sandy sediment with seagrasses Halodule uninervis and H. pinifolia , 1 m, K. Neil, 2001 NMV J53202 (male, 9.1 mm). Paratypes, same locality, 5 m, NMV J53203 (2 females, 6.3, 7.1 mm).

Description. Male. Body 3.1 times as long as greatest width at pereonite 3, dorsal surface smooth, pale, ornamented with numerous, evenly spaced, small distinct chromatophores; without dorsal sculpture. Head 1.6 times as wide as long, 0.57 times width of pereonite 3, middorsum evenly domed, without ornamentation, with shallow transverse depression near anterior margin, front barely excavate, strongly tapering in front of eyes; eye bulging, 0.37 times as long as median head length. Pereonite 1 0.75 width of pereonite 3, lateral margin with definite rounded obtuse angle one-third from anterior suture, posterior two-thirds with parallel margins. Pereonite 2 with rounded anterolateral margins, narrower at posterior suture. Pereonite 3 lateral margin evenly convex. Pereonite 4 lateral margin broadly convex. Pleotelson 1.2 times as long as greatest width; tapering beyond pleonite 1 suture to 0.8 of greatest width to an obtuse angle at 0.75 length, then more steeply to excavate posterior margin.

Antenna 1 flagellum 0.9 length of peduncle, with 12 pairs of aesthetascs. Antenna 2 0.7 body length; article 4 3.6 times as long as wide; article 5 6.2 times as long as wide; flagellum with 21 articles, as long as peduncle.

Maxilla 2 outer lobe expanded, with 17 long plumose setae. Maxillipedal basal endite longer than wide, with 1 coupling hook, apex setose. Maxillipedal palp 2.0 times as long as greatest width; article 3 1.3 times as long as wide. Epipod 1.5 times as long as wide, with broad oblique apex.

Pereopods with dense mat of setation on flexor margins of merus–propodus. Pereopod 1 propodus 1.7 times as long as greatest depth, palm excavate, mesial face setose; dactylus almost linear except for curved unguis, reaching back to base of carpus. Pereopod 2 propodus as long as merus and carpus together, 2.9 times as wide as long. Pereopod 4 propodus 3.3 times as wide as long. Pereopod 7 propodus 3.8 times as wide as long.

Penial plate 1.6 times as long as wide, slightly waisted, with rounded apex.

Pleopod 2 with appendix masculina 1.25 times as long as endopod, with rounded apex, with few superficial spines. Uropod 3.9 times as long as distal peduncle width; endopod 0.28 length of peduncle, mesial length 0.8 proximal suture length, suture almost at right-angles to long axis, distal margin truncate, at 75° to long axis, lateral margin straight and with curve between lateral and distal margins; with 1 seta.

Female. Body 2.6 times as long as greatest width at pereonite 3. Head twice as wide as long. Pereonite 1 0.8 width of pereonite 3, lateral margin more evenly curved than in male. Pereonite 2 with rounded anterolateral margins, parallel-sided over posterior two-thirds. Pleotelson 1.1 times as long as greatest width; tapering to 0.7 of greatest width beyond pleonite 1 suture to an obtuse angle at 0.75 length, then more steeply to excavate posterior margin.

Antenna 2 0.7 body length; article 4 3.2 times as long as wide; article 4 6.9 times as long as wide; flagellum with 16 articles, 1.2 times length of peduncle. Maxilla 2 outer lobe not expanded. Pereopods without mat of setae on flexor margins.

Etymology. Karumba , from the town where the specimens were found, noun in apposition.

Distribution. Australia, Queensland, west coast of Cape York at c. 17°S; 1 m depth.

Remarks. Synidotea karumba was compared with others above.