Colopisthus canna, MOORE & BRUSCA, 2003

MOORE, WENDY & BRUSCA, RICHARD C., 2003, A monograph on the isopod genus Colopisthus (Crustacea: Isopoda: Cirolanidae) with the description of a new genus, Journal of Natural History 37 (11), pp. 1329-1399 : 1342-1349

Colopisthus canna new species

(figures 5–9)

Type material examined. H  , female ( CRU-1969 ), five female paratypes in alcohol ( CRU-3276 ) and one SEM prepared paratype mounted on stub ( CRU-3277 ); Cape Verde Islands, St Vincent; Station No. 37, Anton Brunn, Atlantide Expedition (Cat. No. ZMUC CRU-1969 ) .

Diagnosis. Pleon with two free pleonites (plus pleotelson). Antenna 1 flagellum three-articulate. Antennae 2 flagellum four-articulate. Maxilliped endite with five circumplumose setae and two coupling setae. P-1 to P-3 merus with two or three molariform setae on inferior margin. P-1 carpus with two connate spines on inferior margin. Carpus of P-5 with one biplumose seta on anterior-distal margin; P-6 with three biplumose setae on anterior-distal margin; P-7 with 11 biplumose setae on anterior-distal margin. Pl-3 exopod with complete transverse suture.

Description of female

Antennae. Antenna 1 peduncular articles 1 and 2 with slender and palmate setae, article 3 with slender setae; articles 2 and 3 subequal in length; article 4 with two biplumose setae. Antenna 1 flagellum three-articulate; first article much longer than distal two articles; all flagellar articles with jointed aesthetascs. Antenna 2 peduncle articles 2–5 with slender and biplumose setae; flagellum four-articulate, all with cluster of slender setae in anterior-distal region.

Maxilliped. Endite with five circumplumose setae and two coupling setae. Palp article 1 medial margin with fine and slender setae; article 2 lateral margin with one slender seta, and medial margin with fine and slender setae; article 3 with slender setae on lateral and medial margins; article 4 with one slender seta on disto-lateral angle, and slender setae on disto-medial angle; terminal article subquadrate with six apical setae (broken on holotype).

Maxillae. Maxilla 1 lateral lobe with two stout, five forked and three uniserrate setae; medial lobe with two slender and three stout biplumose setae (one biplumose seta missing from holotype). Maxilla 2 outer lobe with three uniserrate setae on distal margin and fine setae on lateral margin; medial lobe with three uniserrate setae; gnathal lobe with one slender seta at base (below outer lobe), apical margin with one large circumplumose, four stout biplumose and two slender setae.

Mandible. Spine row with 13 large spines; molar process with approximately 15 small acute marginal spines; proximal palp article without setae; middle article with one slender, seven biserrate and two unequally biserrate setae; distal article with nine biserrate setae.

Pereopods 1–3. Ischium of P-1 without setae, P-2 and P-3 with molariform seta near inferior-distal angle and stout seta on superior-distal angle, P-3 with stout setae on inferior margin. Merus with two or three molariform setae on inferior margin and a cluster of stout setae on inferior-distal angle; distal margin deeply incised (notched) on anterior surface. Carpus subtriangular, inferior margin much longer than superior margin; with cluster of stout setae on inferior distal angle; P-1 with two connate spines on inferior margin. Propodus with complex setae and connate spines on inferior margin as figured; P-1 with two complex setae and four or five connate spines; P-2 with two complex setae and two or three connate spines; P-3 with one complex seta, one robust seta and no connate spines.

Pereopods 4–7. Basis with one or two biplumose setae at inferior distal angle. Ischium with two to five clusters of stout setae on inferior margin; P-5 to P-7 with two biplumose setae at superior-distal angle. Carpus of P-5 with one biplumose seta on anterior-distal margin; P-6 with three biplumose setae on anterior-distal margin and approximately two long biplumose setae at superior-distal angle; P-7 with 11 biplumose setae on anterior-distal margin and approximately five long biplumose setae at superior-distal angle. Propodus inferior distal angle with one stout seta and one reduced complex seta; posterior-distal margin with one stout seta (drawn in dashed lines in figure 8); superior-distal angle with one stout and two slender setae. Dactyli with large secondary unguis and no accessory setae.

Pleopods. Pl-1 to Pl-4 peduncle with three coupling setae on medial margin; Pl-5 peduncle subovate, with one biplumose seta on lateral margin. Pl-2 peduncle with one biplumose seta on lateral margin. Pl-3 to Pl-5 exopod with complete transverse suture. Pl-1 endopod with approximately nine PMS; exopod with approximately 14 PMS. Pl-2 to Pl-4 endopod with approximately eight PMS; exopod with 19–21 PMS. Pl-5 endopod subovate, without setae; exopod with approximately 12 PMS.

Uropod. Endopod with slender and palmate setae; two robust setae on medial margin and one robust seta on lateral margin; apex broadly rounded, with approximately five long slender setae. Exopod with slender setae and two robust setae on medial margin; apex rounded, with approximately three or four long slender setae; lateral margin with a continuous row of short slender setae; proximal lateral margin with dorsal fold.

Distribution

This species has been collected only from St Vincent, one of the Cape Verde Islands.

Remarks Males of this species have not yet been collected.

Etymology

This species name is taken from the Latin word, canna , for sugar cane, the principal ingredient of rum, a favoured libation in the tropical Atlantic region.