Cynopoecilus nigrovittatus, M., 2002

M., Wilson J. E., 2002, The annual fish genus Cynopoecilus (Cyprinodontiformes: Rivulidae): taxonomic revision, with descriptions of four new species, Ichthyol Explor. Freshwaters 13, No. 1, pp. 11-24 : 20-22

Cynopoecilus nigrovittatus , new species ( Fig. 5 )

Holotype. MCP 26931 , male, 44.3 mm SL; Brazil: Rio Grande do Sul: Montenegro, rio Cai floodplains (about 29°45'S 51°30'W); W. J. E. M. Costa & A. C. Bacellar, 17 Sept 1999.

Paratypes. Brazil: Rio Grande do Sul: MCP 26932 , 5 males, 37.0- 40.7 mm SL, 5 females, 24.6-31.2 mm SL ; UFRJ 4976 , 21 males, 28.042.1 mm SL, 24 females, 25.5-32.2 mm SL ; UFRJ 5012 , 4 males, 35.8-40.8 mm SL, 2 females,28.8-31.1 mmSL (c&s); collected with holotype. - UFRJ 4977 , 14 males, 26.4-34.0 mm SL, 9 females, 20.0- 24.8 mm SL ; UFRJ 5039,31 males, 20.0- 33.3 mm SL, 15 females, 19.0- 25.2 mm SL; rio Cai floodplains , road BR-386 ; W. J. E. M. Costa & A. C Bacellar, 17 Sept 1999. - UFRJ 4820 , 15 males, 22.7-30.7 mm SL, 15 females, 16.5-24.2 mm SL; 10 km S of Sao Jeronimo; W. J. E. M. Costa, D. Belote, F. Pupo & D. Almeida, 16 Jul 1998 . - UFRJ 4829,15 males, 18.3- 27.6 mm SL, 28 females, 18.1-21.9 mm SL ; UFRJ 5231 , 4 males, 22.7-26.5 mm SL, 2 females, 18.5- 18.6 mm SL (c&s); rio Jacui floodplains, between General Camara and Sao Jeronimo ; W. J. E. M. Costa, D. Belote, F. Pupo & D. Almeida, 16 Jul 1998 .

Diagnosis. Differs from all its congeners and species of closely related genera ( Campellolebias , Leptolebias ) by dorsal profile of head of adult male strongly concave (vs. straight to slightly concave), lateral body stripes of male black (vs. dark reddish brown), caudal fin of male with a bright blue zone along its posterior margin (vs. absent). It is also distinguished from all other species of the genus by the combination of the following characters: the whole caudal fin of male with dark spots (vs. faint spots restricted to the dorsal portion of the fin or caudal spots absent in C. melanotaenia ), pectoral-fin length of male 19.6- 23.4 % SL (vs. 16.1-18.5 in C.fulgens ), longitudinal rows of spots on body of male light blue (vs. bright golden in C.fulgens ), pelvic-fin length 63- 7.2 % SL in male, and 6.4-7.4 in female (vs. 4.7-5.6 in male and 4.1-53 in female of C. intimus ), dark brown irregular marks on dorsum below dorsal fin of male (vs. rounded blotches in C. intimus ), 15-17 supraorbital neuromasts (vs. 17-20 C. multipapillatus ), and one to three neuromasts per scale of the lateral line (vs. five to nine in C. multipapillatus )

Description. Morphometric data are given in Table 5 . Body slender, slightly compressed, body width approximately 1.5 in body depth in larger males. Longest body depth on a vertical through pelvic-fin base. Dorsal profile concave on head in female and strongly concave in male, convex between nape and posterior end of dorsal-fin base, approximately straight on caudal peduncle; ventral profile between lower jaw and end of anal-fin base smoothly convex to approximately straight in male, convex in female, and approximately straight on caudal peduncle of both sexes.

Tip of dorsal and anal fins pointed and long in male, rounded and short in female. Caudal fin rounded to subtruncate. Pectoral fin elliptical. Posterior margin of pectoral fin just posterior to a vertical through pelvic-fin base in male, and just anterior to that vertical in female. Tip of pelvic fin reaching base of genital bulb. Pelvic fins separated by a small interspace. Dorsal-fin origin in a vertical through genital bulb in male, and through anus in female. Anal-fin origin in a vertical through base of 2“* or 3rd dorsal-fin ray in male, and base of 4th or S'1, in female. Dorsal-fin rays 17-20; anal-fin rays 23-27; caudal-fin rays 28- 30; pectoral-fin rays 13-14; pelvic-fin rays 5-7. Longitudinal series of scales 26-28, transverse series of scales 9, and scale rows around caudal 21 peduncle 12. Ctenii-like contact organs on caudal peduncle side of male. No contact organs on pectoral-fin of male. Supraorbital neuromasts 15- 17. One to three neuromasts per scale of lateral line. Gill-rakers on first branchial arch 2 + 9. Total vertebrae 28-29.

Coloration. Male: side of body light yellowish brown; a broad, horizontal stripe on midline of body and head, black on body and dark brown on head, between lower jaw and caudal-fin base; on body side and opercular region stripe overlapped by longitudinal series of spots, greenish blue on opercle and bright blue on body, each spot on center of each scale; a narrower black stripe, ventral to median stripe, between pectoral-fin base and end of anal-fin base, anteriorly overlapped by small pale light blue spots; dark brown pigment concentrated on posterior borders of dorso-lateral scales, forming irregular marks. Dorsum light brown with small rounded dark reddish brown spots. Venter white. Suborbital bar dark reddish brown, usually posteriorly followed by similar, lighter marks. Iris yellow, with a vertical dark brownish red bar; dark reddish brown pigment concentrated on posterior portion of iris. Dorsal fin greenish hyaline, anal fin hyaline, caudal fin pale reddish hyaline; small dark brown spots on dorsal and caudal fins, and faint similar gray spots on anal fin; sometime? a narrow blue lines on dorsal and ventral edges of caudal fin; a broad bright blue zone along posterior border of caudal fin. Pectoral fin hyaline. Pelvic fin dark gray.

Female: color pattern as in male, but lateral longitudinal stripes light gray, overlapped by a few longitudinal series of bright greenish blue small spots on center of each scale, and unpaired fins hyaline ivith faint gray small spots.

Distribution. Lower rio Jacui basin, southern Brazil ( Fig. 1 ).

Etymology. From the Latin nigrum (black) and vittatum (with ribbon), an allusion to the black stripes of the male. An adjective.

Figures

Fig. 5. Cynopoecilus nigrovittatus, MCP 26931, holotype, male, 44.3 mm SL (one day after collection); Brazil: Rio Grande do Sul: Montenegro.

Fig. 1. Geographic distribution of Cynopoecilus: C. melanotaenia (*), C.fulgens (■), C. infimus (*), C. nigrovittatus (♦), and C multipapillatus (*}. Arrows indicate type localities; symbols may represent more than one locality. Scale bar 70 km.

Tables

Table 5. Morphometric data for holotype (H) and nine paratypes of Cynopoecilus nigrovittatus.,

		males				females
	H	paratypes
	MCP 26931	UFRJ 4976	UFRJ 4976	UFRJ 4820	UFRJ 4820	UFRJ 4976	UFRJ 4976	UFRJ 4976	UFRJ 4820	UFRJ 4820
SL [mm]	44.3	412	34.7	29.8	26.8	29.3	27.3	26.3	24.2	22.7
In percents of standard length
Body depth	25.9	28.3	30.1	28.1	29.7	27.1	29.4	28.8	26.6	26.9
Caudal peduncle depth	12.8	14.1	15.0	14.3	15.0	13.9	14.6	13.1	13.2	13.1
Predorsal length	54.7	54.9	57.4	57.3	57.9	63.2	62.9	60.7	62.2	60.0
Prepelvic length	47.7	49.1	49.0	48.8	50.6	54.6	55.0	53.0	523	53.8
Length of dorsal-fin base	28.3	29.8	28.3	31.2	31.6	23.7	26.9	27.7	25.8	53.8
Length of anal-fin base	24.2	24.8	23.5	27.1	26.8	19.4	19.6	20.2	21.0	19.8
Caudal-fin length	32.6	34.6	33.2	33.1	33.6	29.3	33.1	32.2	32.0	31.9
Pectoral-fin length	19.6	22.2	22.9	23.4	23.1	19.1	22.3	21.4	19.5	19.5
Pelvic-fin length	64	6.8	7.1	7.2	6.3	6.3	5.9	6.3	6.7	7.2
Head length	28.0	29.0	31.8	28.1	28.7	29.5	31.2	29.8	28.1	27.6
In percents of head length
Head depth	72.6	69.2	71.4	70.2	72.0	70.8	76.1	74.0	72.0	71.7
Head width	63.8	61.9	66.5	66.5	69.1	70.3	68.3	69.3	69.2	75.3
Snout length	142	13.3	12.3	12.6	12.8	13.1	13.5	13.2	13.4	13.1
Lower jaw length	25.5	26.3	25.1	25.4	27.2	21.3	22.2	20.2	23.1	21.0
Eye diameter	315	32.4	33.2	36.4	37.9	36.0	33.7	36.9	37.0	39.2