Bambalocra, Bruce, Niel L., Welicky, Rachel L., Hadfield, Kerry A. & Smit, Nico J., 2019

Bruce, Niel L., Welicky, Rachel L., Hadfield, Kerry A. & Smit, Nico J., 2019, A new genus and species of fish parasitic cymothoid (Crustacea, Isopoda) from the Indian Ocean coast of South Africa, with a key to the externally attaching genera of Cymothoidae, ZooKeys 889, pp. 1-15 : 1

Genus Bambalocra gen. nov.

Type species.

Bambalocra intwala sp. nov.; original designation.

Etymology.

Bamba is an isiZulu word meaning 'to grip’, combined with the ending - locra, alluding to related genera such as Anilocra ; the name refers to the isopod gripping onto its host. Gender is female.

Diagnosis of female.

Cephalon anterior margin wide, with ventral posteriorly directed rostrum separating bases of antennulae; posterior margin not trilobed. Body weakly vaulted; coxae 2-6 ventral, not visible in dorsal view; posterolateral margins of pereonites 6 and 7 posteriorly produced, that of pereonite 7 extending posteriorly along pleon to pleonites 2 or 3. Pleonites all wide, posterolateral margins narrowly rounded to acute, pleonite 1 largely visible; pleonites 1-2 ventrolateral margins not produced. Antennula and antenna both slender, antenna longer than antennula; bases widely separate. Pleopods 1-2 lamellar, pleopods 3 and 4 endopod with small, weak lobes, pleopod 5 endopod with small fleshy lobes; peduncle of pleopods 2-5 with fleshy medial lobes present.

Additional characters.

Body twice as long as wide. Eyes posterolateral in position, less than 0.3 width of cephalon. Pereonite 2 shortest, 5 and 6 longest; pereonite 5 widest. Pleotelson flat. Mandible palp articles robust; article 3 broadly rounded, as long as proximal width. Maxillula with 4 terminal RS. Maxilla with 1 and 2 small recurved RS each on medial and lateral lobe, respectively. Maxilliped articles broad, article 3 with 3 RS. Pereopods 1-5 subequal in length, 6 slightly longer than 1-4; pereopod 7 longer than pereopod 6. Brood pouch formed by two large oostegites arising from pereonite 6, smaller alternately overlapping oostegites arising from pereonites 1-4, posterior pocket present. Uropod rami subequal in length, visible in dorsal view, slightly exceeding pleotelson posterior margin.

Male

(juvenile). Smaller, narrower, less ovate than female; pereonites 2-7 posterolateral angles rounded, not or weakly posteriorly produced. Appendages similar to female, except folds on pleopods 3-5 endopod absent.

Remarks.

Bambalocra gen. nov. can immediately be identified and distinguished from all other marine cymothoid genera by coxae 2-5 being ventral in position, not forming part of the body outline and not or barely visible in dorsal view, all are posteriorly acute, and the posterolateral margins of pereonite 6 and 7 are posteriorly produced and broadly rounded. The antennula bases are widely separated, with both antennula and antenna slender.

Bambalocra gen. nov. superficially resembles Renocila in having a relatively broad body with a weakly vaulted dorsum and the posterolateral margins of pereonites 6 and 7 expanded and posteriorly directed; in dorsal view the anterior margin of the cephalon appears similar, being weakly produced and wide. Unlike Renocila the ventral rostrum is triangular (vs. broadly truncate in Renocila ) and is posteriorly directed separating the antennular bases (vs. not posteriorly directed between the antennular bases); pleonite 1 in Bambalocra is not markedly narrower than the remaining pleonites (vs. narrower, which is diagnostic for Renocila ). Most species of Renocila have the antennula both longer and larger than the antenna, usually with strongly flattened expanded articles, while in Bambalocra the antennula is shorter than the antenna and both are slender; in most species of Renocila the coxae of pereonites 2-4 or 2-5 are visible in dorsal view.

Both Nerocila and Creniola have the posterior margin of the cephalon strongly trilobed, contrasting strongly to that of Bambalocra . Species of Nerocila are characterised by having pleonites 1 and 2 with ventral processes, while in Creniola the pleon is as wide or wider than the pereon. In both these genera the coxae are conspicuous in dorsal view. Most species of Anilocra have a relatively elongate body, with a strongly vaulted dorsum; the coxae and the posterolateral margins of pereonites 5-7 are neither expanded nor posteriorly produced.