A monograph on the isopod genus Colopisthus (Crustacea: Isopoda: Cirolanidae) with the description of a new genus Author MOORE, WENDY Author BRUSCA, RICHARD C. text Journal of Natural History 2003 2003-06-30 37 11 1329 1399 http://www.tandfonline.com/doi/abs/10.1080/00222930110108335 journal article 10.1080/00222930110108335 1464-5262 5260073 Colopisthus tresesquinas new species (figures 28–34) Synonymy. Colopisthus parvus Müller, 1993: 212–218 , figures 72–96 (misidentification; not C. parvus : Richardson, 1902 ). Type material examined . H  , female ( ZMB Cat. No. 26973) ; one male , three female and two juvenile paratypes ; Colombia , Santa Marta , intertidal from Sargassum ; collected by H. G. Müller. Diagnosis . Pleon with three free pleonites. Antenna 1 flagellum three-articulate. Antennae 2 flagellum seven-articulate. Maxilliped endite with four circumplumose setae and two coupling setae; palp articles 2 and 3 partly fused. P-1 to P-3 merus with two or three molariform setae on inferior margin. Carpus of P-5 with one biplumose seta on anterior-distal margin; P-6 with three biplumose setae on anteriordistal margin; P-7 with seven biplumose setae on anterior-distal margin. Pl-3 exopod with complete transverse suture. Description of female Dorsal surface of pereon and pleon with fine setae. Antennae . Antenna 1 peduncular articles 1–3 with slender and palmate setae, article 4 with palmate setae; flagellum three-articulate, first article much longer than distal two articles; all flagellar articles with slender setae and jointed aesthetascs. Antennae 2 peduncular articles 2 and 3 with slender setae on anterior margin, articles 4 and 5 with biplumose and slender setae as figured; flagellum seven-articulate, all with cluster of slender setae in anterior-distal region and one or two slender setae in posterior-distal region. F. 28. Colopisthus tresesquinas , female holotype: (A) lateral aspect; (B) dorsal aspect. Maxilliped . Endite with four circumplumose setae and two coupling setae. Palp article 1 with a jointed slender seta on medial margin; articles 2 and 3 partly fused, lateral margins with fine setae, lateral and medial margins with jointed slender setae; article 4 with one jointed seta on disto-lateral angle, one uniserrate and approximately five jointed slender setae on disto-medial angle; terminal article length greater than width, with approximately six slender (some jointed) and two uniserrate apical setae. F. 29. Colopisthus tresesquinas , female holotype: (A) antenna 2; (B) antenna 1; (C) right maxilliped; (D) maxilla 1; (E) right mandible; (F) frontal lamina, clypeus, labrum; (G) maxilla 2. F. 30. Colopisthus tresesquinas , female holotype: (A) right pereopod 2; (B) right pereopod 3; (C) right pereopod 1; (D) right pereopod 1, detail of propodus. Internal gland-like structures of pereopod 1 shown. Maxillae . Maxilla 1 lateral lobe with one stout, seven forked and three uniserrate setae; medial lobe with one small biplumose, one slender and three stout biplumose setae. Maxilla 2 outer and medial lobes with three uniserrate apical setae; outer lobe with fine setae on lateral margin; gnathal lobe with one slender seta at base (below outer lobe), apical margin with one large circumplumose, one stout, one slender and three stout biplumose setae. F. 31. Colopisthus tresesquinas , female holotype: (A) right pereopod 4; (B) right pereopod 5; (C) right pereopod 6; (D) right pereopod 7; (E) right pereopod 7 detail of carpus. Mandible . Spine row with 14 large spines; molar process with approximately 21 small acute marginal spines; proximal palp article with one slender seta on lateral margin; middle article with two slender, six biserrate and three unequally biserrate setae; distal article with eight biserrate setae. F. 32. Colopisthus tresesquinas , female holotype: (A) left pleopod 1; (B) right pleopod 2; (C) left pleopod 5; (D) left pleopod 4; (E) left pleopod 3. F. 33. Colopisthus tresesquinas , female holotype: (A) telson-uropod; (B) right uropod. F. 34. Colopisthus tresesquinas , male: (A) penes; (B) antenna 2; (C) antenna 1. Pereopods 1–3 . Ischium with two stout setae on inferior margin and one stout seta on superior-distal angle and anterior-distal margin; P-2 and P-3 with a molariform seta near inferior-distal angle. Merus with two or three molariform setae on inferior margin and one or two stout setae on superior-distal angle; distal margin deeply incised (notched) on anterior surface; P-1 with a connate spine on inferiordistal angle. Carpus subtriangular, inferior margin much longer than superior margin; with cluster of stout setae on inferior distal angle and two or three connate spines on inferior margin. Propodus with complex setae and connate spines on inferior margin as figured; P-1 and P-2 with two complex setae and four or five connate spines; P-3 with two complex setae and two connate spines. Pereopods 4–7 . Ischium with two or three clusters of stout setae on inferior margin; P-5 to P-7 with one or 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, two long biplumose setae at superior-distal angle; P-7 with seven biplumose setae on anterior-distal margin and approximately five long biplumose setae at superior-distal angle. Propodus inferior distal angle with two stout setae; posterior-distal margin with one stout seta; superior-distal angle with one stout, one or two slender and one biplumose seta. Pleopods . Pl-1 to Pl-4 peduncle with one biplumose and three coupling setae on medial margin. Pl-2 to Pl-5 lateral margin of peduncle with one stout seta. Pl-3 to Pl-5 exopod with complete transverse suture. Pl-1 to P-4 endopod with approximately five or six PMS; exopod with approximately 13–16 PMS. Pl-5 endopod subovate, without setation; exopod with approximately seven PMS. Uropod . Endopod with slender and palmate setae, two robust setae on medial margin and one robust seta on lateral margin; apex broadly rounded. Exopod with slender and two robust setae on medial margin; apex rounded, with five long slender setae; lateral margin with a continuous row of short slender setae; without lateral fold. Description of male As described for female. Appendix masculina missing from specimen; figured by Müller (1993). Secondary sexual characters typical of genus. Distribution This species is so far known only from the intertidal shores of Santa Marta, Colombia , where it was collected from the brown alga Sargassum . Etymology This species is named after Tresesquinas rum, one of the gentle rums of Colombia .