Kagalana, Bruce, Niel L., 2008

Bruce, Niel L., 2008, New species and a new genus of Cirolanidae (Isopoda: Cymothoida: Crustacea) from groundwater in calcretes in the Pilbarra, northern Western Australia, Zootaxa 1823, pp. 51-64 : 52-53

Kagalana gen. nov.

Type species: Kagalana tonde sp. nov., here designated (monotypic).

Diagnosis. Head with rostral point. Clypeus ventrally flat, not blade-like, not projecting. Pleonites 4 and 5 narrow, laterally overlapped by margins of pleonite 3 and pleonite 5 narrower than the pleotelson anterior margin; pleonite 1 and most of pleonite 2 not visible in dorsal view. Pereopod 1 robust, propodus expanded, dactylus haptorial; pereopods 2–7 ambulatory, slender. Pereopods 1–3 with ischium superior distal margins weakly produced, setose; merus superior distal margin weakly produced, not overriding propodus; pereopods 2 and 3 merus inferior margin RS not molariform; pereopods 5–7 basis without long PMS, ischium and merus distally without long setae. Penial processes present on sternite 7 as mutually adjacent papillae. Pleopod 1 endopod narrow, half as wide as exopod. Pleopod 2 appendix masculina basally inserted, apex sub-acute.

Description. Head wide, approximately 75% as wide as pereonite 1, anterior margin evenly rounded. Body surfaces unornamented; pereonite 1 about 1.7 times as long as pereonite 2 in dorsal view. Pleon unornamented, about 9% BL, with 4 visible unfused segments, pleonite 1 and most of pleonite 2 largely concealed by pereonite 7; pleonite 2 epimera not produced;. Pleotelson without longitudinal carinae, ridges or without tubercles; posterior margin with PMS and RS.

Antennule peduncle articles collinear, articles 1 and 2 fused; peduncular article 2 not at right angles to article 1; article 3 well developed, about as long as combined lengths of articles 1 and 2; flagellum shorter than peduncle; without callynophore. Antenna peduncle comprised of 5 articles, peduncular articles 1–3 shortest, articles 4 and 5 longest, 5 longer than 4; flagellum about as long as peduncle.

Frontal lamina lateral margins parallel; ventrally flat, without lateral angles, anteriorly rounded; posteriorly abutting clypeus; approximately 2 times as long as basal width, not projecting anteroventrally from posterior. Clypeus ventral surface not projecting relative to frontal lamina. Mandible incisors wide, right incisor tricuspidate; spine row with 4–5 RS. Maxillule mesial lobe with 3 CP RS. Maxilliped palp articles 3 and 4 mesial margin lobed; lateral margins of articles 2–5 with long setae; articles 3 and 4 distal margin width greater than proximal margin of article 4 and 5 respectively; endite with 1 coupling hook.

Pereopods 1–7 dactylus with small secondary unguis present. Pereopod 1 dactylus longer than palm; complex RS opposing dactylus. Pereopod 7 basis not noticeably broader in distal half compared to proximal half; margins with few discontinuous setae; ischium and merus not flattened, distal margin weakly expanded, inferior margins with few setae; inferodistal angles of ischium, merus and carpus with low cuticular nodules.

Pleopod 1 rami lamellar; endopod narrow, 3.5 times as long as wide. Pleopod 2 appendix masculina longer than endopod. Pleopods 1–5 with PMS present on all exopods and endopods of pleopods 1 and 2; endopods 3–5 without PMS, smaller (0.7–0.8) than exopods; endopod of pleopod 5 without proximomesial lobe. Uropod peduncle mesial margin strongly produced; exopod lateral margin not excised.

Females. Ovigerous and non-ovigerous females similar to males but slightly larger. Brood pouch made up of 4 pairs of oostegites arising from coxae 2–5, the posterior pair being largest, extending over most of the marsupium (anteriorly to sternite 3).

Remarks. Kagalana gen. nov. is characterised by and can be identified by the typical cirolanid body shape (see Bruce 1986; Brusca et al. 1995), together with the antennule peduncle and flagellum being short (extending no further than the anterior of pereonite 1), pleonites 4 and 5 narrow, laterally overlapped by margins of pleonite 3 and pleonite 5 narrower than pleotelson anterior margin, pereopod 1 being robust and haptorial and the inferior margins of the merus of pereopods 2 and 3 lacking molariform setae.

Relationships. The most similar genus is Speocirolana Bolívar y Pieltain, 1950, a genus of 12 species endemic to Mexico and Texas, which differs to Kagalana in the large size (adults 14–33 mm) of the species, pleonites 4 and 5 subequal in width and both narrower than the pleotelson anterior margin, in having haptorial and robust pereopods 2 and 3 and prominent penial processes; the palm of pereopods 1–3 typically has several large robust setae, but there is no robust seta opposing the base of the dactylus. Speocirolana was first established as a subgenus of Cirolana Leach, 1818 , Bowman (1964) later elevating it to genus on the basis that pereopods 1–3 were ‘prehensile’. Bowman (1964) did not rediagnose the genus and, surprisingly given the number of described species, no revised diagnosis to the genus has since been given. Botosaneanu et al. (1998) offered some additional states ‘apparently demonstrating monophyly’, though the distribution and significance of the states mentioned was not discussed; some included characters such as ‘pereopods 4–7 ambulatory’, a state that is widespread in the genera close to Cirolana , are of little diagnostic value.

Kagalana shows few obvious affinities to other genera. The form of pleonites 4 and 5 and pereopod 1 is similar to but not the same as that of Speocirolana , but convergence can be supposed. The morphology of the antennule, antenna, mouthparts and uropods are most similar to that of Cirolana while the complex robust seta opposing the base of the dactylus of pereopod 1 could be interpreted as similar to genera related to Metacirolana Kussakin, 1979 (see Bruce 1986; Brusca et al. 1995). At present I regard the genus as of uncertain affinities, but probably derived from a Cirolana -like ancestor.

Many cave-dwelling cirolanids have long antennules and antennae, including relatively long flagellae, and Kagalana is distinctive in having a very short antennule peduncle and flagellum.

Etymology. Kaga is an Aboriginal word for a water hole; combined with –lana to indicate the family affinity; gender female.