Colopisthus parvus : Richardson 1902
Creators: name: MOORE, WENDY
name: BRUSCA, RICHARD C.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Cirolanidae
Colopisthus
Colopisthus parvus

description: Colopisthus parvus Richardson, 1902   
(figures 15–22)  
 Colopisthus parvus Richardson, 1902: 289, pl. XXXVIII, figures 33–36; Richardson 1905: 137, figure 119; Kensley and Schotte, 1989: 147, figure 66A; Kensley, 1994: 319.   
 Not Colopisthus parvus. Monod, 1952; Menzies and Glynn, 1968; Müller, 1993: figures 72–96.   
 Type material examined. (1) Syntypes (co-types), females (USNM 24867, Acc. No. 37555): Bermuda, Bailey Bay, low water in coralline algae; Yale University Expedition 1898; collected by A. E. Verrill.   
 Other material examined. (2) YPM 3338; Bermuda; collected by A. E. Verrill; one female specimen. (3) YPM 3341; Bermuda, St George’s Parish, Castle Harbor, Waterloo; A. E. Verrill Bermuda Expedition 1901; one male specimen. The following voucher specimens from Kensley (1994). (4) YPM 9574; Bermuda, Devonshire Bay; 1985, collected by M. F. Gable; one female and one juvenile specimen. (5) YPM 9684; Bermuda, Devonshire Bay, 0.3 m depth; 1988; collected by E. A. Lazo-Wasem; 18 female, five male and 12 juvenile specimens. (6) YPM 9685; Bermuda, St George’s Parish; 1988, collected by E. A. Lazo-Wasem and J. Hamilton; one male specimen. (7) YPM 9632; Bermuda, Hamilton Parish, Shelly Bay, 0.3 m depth; 1987, collected by M. F. Gable; three female specimens.   
 Diagnosis. Pleon of female with two free pleonites; males with three free pleonites. Lateral margins of pereonite 1 without crenulations or with weak crenulations. Antenna 1 flagellum three-articulate. Antennae 2 flagellum six-articulate. Maxilliped endite with five circumplumose setae and two coupling setae. Merus of P-1 to P-3 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 10 biplumose setae on anterior-distal margin. Pl-3 exopod with partial transverse suture.   
 Description of female   
 Antennae. Antenna 1 peduncular article 1 with slender and palmate setae; articles 2–3 with slender setae only; article 3 longest and narrowest; article 4 without setae; flagellum three-articulate, first article much longer than distal two articles, all flagellar articles with slender setae and jointed aesthetascs. Antennae 2 peduncular article 1 minute, articles 2 and 3 with slender setae, articles 4 and 5 with biplumose and slender setae on distal margin; flagellum six-articulate, all with clusters of slender setae in the 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 slender setae and medial margin with fine and slender setae; articles 3 and 4 with slender setae on lateral and medial margins, article 4 with one uniserrate seta on distal medial angle; terminal article subquadrate, with slender and uniserrate apical setae.   
 Maxillae. Maxilla 1 lateral lobe with one stout, six forked and four uniserrate setae; medial lobe with one small slender and three stout biplumose setae. Maxilla 2 outer lobe with three uniserrate setae, fine setae on lateral margin; medial lobe with four uniserrate setae; gnathal lobe with one slender seta at base (below outer lobe), fine setae on medial margin; apical margin with one large circumplumose, five stout biplumose and slender setae.   
 Mandible. Spine row with 14 large spines; molar process with approximately 20 small acute marginal spines; proximal palp article with one slender seta on lateral margin; middle article with one slender, seven biserrate and four unequally biserrate setae; distal article with 10 biserrate setae.   
 Pereopods 1–3. Ischium on P-1 and P-2 without setae on inferior margin; P-3 with stout setae on inferior margin and superior-distal angle, molariform seta near inferior-distal angle. Merus with two or three molariform setae on inferior margin and clusters of stout setae on distal angles; 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 three 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 connate spines, P-3 with two complex setae and no connate spines.   
 Pereopods 4–7. Basis with slender and biplumose setae at inferior-distal angle. Ischium with three or four 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 and approximately two long biplumose setae at superior-distal angle, P-7 with 10 biplumose setae on anterior-distal margin and approximately five long biplumose setae at superior-distal angle. Propodus inferior distal angle with one stout and one reduced complex seta; posterior-distal margin with one stout seta; superior-distal angle with one stout 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 exopod with partial transverse suture, Pl-4 to Pl-5 exopod with complete transverse suture. Pl-1 to Pl-3 endopods with approximately six or seven PMS; exopods with approximately 14–19 PMS. Pl-4 endopod with approximately four PMS; exopod with approximately 21 PMS. Pl-5 endopod subovate, without setation; exopod with approximately eight PMS.   
 Uropod. Endopod with 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 five long slender setae; lateral margin with a continuous row of short slender setae.   
 Description of male   
As described for female except for the following. Pleon with three free pleonites. Antennae 1 peduncular article 2 with palmate setae; flagellum composed of two articles, a long proximal article with four jointed aesthetascs; distal article short with two aesthetascs, one biplumose and six slender setae. Antennae 2 peduncular articles 2–5 with slender setae, articles 4 and 5 with biplumose setae; flagellum sixarticulate, all articles with clusters of slender setae in the anterior-distal region. Coxae 4–7 concave.  
 Distribution   
This species is widely distributed in the intertidal areas of Bermuda. So far it has been collected from Bailey Bay, Devonshire Bay, Castle Harbor in St George’s Parish, and Shelly Bay in Hamilton Parish.
description: Published as part of MOORE, WENDY & BRUSCA, RICHARD C., 2003, A monograph on the isopod genus Colopisthus (Crustacea: Isopoda: Cirolanidae) with the description of a new genus, pp. 1329-1399 in Journal of Natural History 37 (11) on pages 1355-1364, DOI: 10.1080/00222930110108335, http://zenodo.org/record/5260073