Moruloidea Baker, 1908

Bruce, N. L., 2003, New genera and species of sphaeromatid isopod crustaceans from Australian marine coastal waters, Memoirs of Museum Victoria 60 (2), pp. 309-369 : 348-350

Moruloidea Baker

Moruloidea Baker, 1908: 150 .— Baker, 1926: 276.— Hale, 1929: 292.— Harrison, 1984a: 383.— Harrison, 1984b: 268.

Vallentinia Stebbing, 1914a: 351 (name preoccupied). Euvallentinia Stebbing, 1914b: 944 (replacement name).—Barnard,

1920: 374.— Nierstrasz, 1931: 218.—Loyola e Silva, 1974: 3.

Type species. Moruloidea lacertosa Baker, 1908 , by monotypy.

Species included and distribution. Moruloidea lacertosa Baker, 1908 ; M. darwinii ( Cunningham, 1871) ; M. tasmaniae ( Baker, 1926) ; M. tumida ( Harrison 1984b) ; M. perionasus sp. nov.; Gondwanan, southern coasts of Australia (WA, SA and Tas.), with one species from Atlantic coast of South America and Falkland Is ( Harrison, 1984b).

Diagnosis of male. Body stout, about twice as long as greatest width, strongly vaulted; dorsal surfaces nodular. Pleotelson with or without median process; posterior margin with simple median notch and shallow exit channel. Coxae of pereonite 5 overlapping those of both pereonite 4 and 6. Pleon of 4 segments, segment 1 largely concealed by pereonite 7, segments 2–4 indicated by 2 distinct suture lines running to lateral margins of pleon. Antennule peduncle article 1 more than twice as long as article 2, articles 1 and 2 robust; article 3 slender, all articles collinear. Antenna articles 3 and 5 proportionally large, article 5 strongly reflexed. Mandible incisor unicuspid, or cusps indistinct; molar process prominent, crushing, provided with marginal scale teeth. Maxilliped palp articles 2–4 with distomesial angle moderately produced, mesial margins with numerous setae. Pereopods all ambulatory, pereopod 1 massive, robust, propodus inferior margin with or without lobelike extension; pereopods 2–7 subsimilar, slender. Penes paired, close set; short, not reaching pleopod peduncles. Pleopods 1–3 both rami with PMS, both rami of subequal length; pleopod 1 with longitudinal axis of both rami weakly oblique, remaining pleopods with longitudinal axis of rami straight. Pleopod 2 with appendix masculina basally attached. Pleopods 3–5 exopods with complete suture. Pleopods 4 and 5 exopod and endopods usually with well-developed transverse thickened ridges; pleopod 5 endopod with 3 lobate scale patches. Uropods attached anterolaterally on pleon, exopod moderate to minute in size; both rami flat not extending beyond posterior margin of pleotelson.

Female. Sexual dimorphism weak; mouthparts not metamorphosed. Brood pouch of the type species of 3 pairs of oostegites on pereonites 2–4; brood housed in 4 pairs of internal pouches (Harrison, 1984). Antenna peduncle and pereopod 1 not as robust as in the male.

Remarks. The genus was revised by Harrison (1984b) who placed Vallentinia Stebbing, 1914a and Euvallentinia Stebbing, 1914b into synonymy.

The coxae of pereonite 5, antenna, antennule, pereopod and pleotelson of Moruloidea are similar to those of Caecocassidias Kussakin, 1967 ( Brandt, 1998), Cymodopsis Baker, 1926 , Ceratocephalus Woodward, 1877 ( Bruce, 1994b), Kranosphaera Bruce, 1992 and Waiteolana Baker, 1926 ( Harrison 1984b). All have coxal plates 5 overlapping both anteriorly and posteriorly, robust pereopod 1 and the posterior margin with a simple shallow exit channel. Most ( Moruloidea , Caecocassidias , Ceratocephalus and Kranosphaera ) have the antenna with peduncle article 5 strongly reflexed and flat uropodal rami with the exopod varying from moderate to absent Kranosphaera . All species of Cymodopsis are inadequately described and the genus is poorly understood. Until Cymodopsis is revised the relationships of these genera to each other and to others will remain unclear.

The presence of a prominent pleotelson process in Moruloidea perionasus sp. nov. and additional data on M. darwinii ( Brandt, 1998) necessitates modification of the diagnosis of Holdich (1984b). M. darwinii was described by Brandt (1998) as having lamellar rami on pleopods 4 and 5.