Rivulus berovidesi, Silva, Rodet Rodriguez, 2015

Silva, Rodet Rodriguez, 2015, Rivulus berovidesi, a new killifish species (Teleostei: Rivulidae) from western Cuba, Zootaxa 3949 (2), pp. 289-296 : 290-294

Rivulus berovidesi , new species

( Figs. 2–6 )

Holotype. CZACC-9.83, adult male, 37.3 mm SL, Sierra de Cajalbana, Pinar del Rio province, Cuba, 220 46’ 31.7’’N, -830 26’ 37.7’’W, 26 February, 2014. R. Rodriguez Silva.

Paratypes. All from Sierra de Cajalbana, Pinar del Rio province, Cuba. Same date and collector as holotype. CZACC-9.84, three males, 31.1–34.7 mm SL; CZACC-9.85, three females, 36.3–37.9 mm SL; MFP 18.00570, two males 32.2–32.8 mm SL and two females 33.7–34.3 mm SL; MNHN 1457 one male 31.3 mm SL and two females 31–35.6 mm SL; MZC 171656 and 171657 two males 32.7–37.9 mm SL respectively and MZC 171658 and 171659 two females 31.4–33.5 mm SL respectively.

Diagnosis. Both males and females of Rivulus berovidesi sp.n. are readily distinguished from Rivulus cylindraceus by the presence of a dark lateral band situated longitudinally along the lateral line, extended from the posterior margin of the eye to the base of the caudal fin (versus a lack of this dark lateral band in Rivulus cylindraceus ). Dorsal fin slightly shifted to the caudal peduncle in relation to the origin of anal fin (1–3 mm) when compared to Rivulus cylindraceus . Frontal scalation pattern in Rivulus berovidesi sp. n. is d - type versus e - type pattern in Rivulus cylindraceus ( Fig. 2 )

Description. Morphometric and meristic data for holotype and 22 paratypes are presented in Tables 1 and 2. Largest examined male 37.9 mm SL; largest examined female 38.0 mm SL. Body subcylindrical anteriorly and compressed posteriorly. Dorsal profile slightly convex from the snout to the posterior base of dorsal fin. Ventral profile slightly convex from the lower jaw to the anal fin origin. Both paired and impaired fins rounded and without filaments. Dorsal fin origin above base of the 5th or 6th anal fin ray. Pectoral fins inserted behind to the posterior margin of opercles. Pelvic fins are the smallest, reaching anus. Dorsal fin rays 6–9, caudal fin rays 15–19, anal fin rays 8–11, pelvic fin rays 4–6 and pectoral fin rays 11–14.

Body and head entirely scaled with cycloid scales. Longitudinal series of scales 34–37, transverse series of scales 9, pre-dorsal scales 21–25. Frontal scalation is d - type pattern. Males of Rivulus berovidesi sp.n. are yellow and orange ventrally, whereas females are less colored. Figure 3 shows sexual dimorphism in this species, which includes differences in color of body and fins as well as females characterized by a distinctive ocellated caudal spot. Females have a diffuse ocellated caudal spot which can extend from the posterior base of the dorsal fin to the upper margin of the caudal fin.

Counts Holotype Paratypes (N=23)

Pre-dorsal scales 23 21 (4) 22 (4) 23 (6) 24 (6) 25 (3) Lateral scales 37 34 (4) 35 (7) 36 (7) 37 (5) Dorsal rays 7 6 (4) 7 (9) 8 (8) 9 (2) Caudal rays 19 15 (1) 16 (2) 17 (9) 18 (7) 19 (4) Anal rays 10 8 (2) 9 (12) 10 (8) 11 (1) Pelvic rays 5 4 (4) 5 (10) 6 (9)

Pectoral rays 11 11 (10) 12 (9) 13 (2) 14 (2)

Color in life. Males ( Fig. 4 ): Body coloration is greenish or olive-green dorsally. There is a wide dark lateral band extended from the posterior margin of the eye to the base of the caudal fin. Ventral ground coloration is yellowish with orange spots reaching the anal fin base. An iridescent blue spot is present behind the margin of opercle in both sexes. Males have an iridescent olive- green spot on the opercle too. Dorsal fin is greenish, caudal fin is slightly greenish on its base and more transparent to the edges. Anal fin is spotted in orange in their base and yellow or yellow- green to the ends. Pelvic fins are yellow and pectoral fins are transparent.

Females ( Fig. 4 ): Body coloration less striking when compared to males. General body coloration brown, darker dorsally than ventrally. Ventral coloration is paler with some small yellowish spots. There is a narrow dark lateral band extended from the posterior margin of the eye to the base of the caudal. Diffuse ocellated caudal spot present which can extends from the posterior base of dorsal fin to the superior margin of caudal fin and sometimes along the caudal fin base too ( Fig. 4 and 5 ). All fins slightly greenish or transparent.

Color in preserved specimens. Preserved specimens with the typical dark lateral band from the posterior margin of the eye to the base of caudal fin in both sexes, although slightly paler than living specimens. Ventral region of the body with a yellowish homogeneous coloration while dorsal region is brownish-gray. Males with a reticulated pattern on scales above lateral dark band ( Fig. 6 ) while females with the diffuse ocellated caudal spot extended from the end of dorsal fin to the superior margin of caudal fin ( Fig. 5 ). All fins with a whitish coloration.

Etymology. The specific name of this new species is given in honor to the Professor Vicente Berovides Alvarez, professor at the Faculty of Biology, Universidad de la Habana, Cuba in recognition of his life-long dedication and contribution to train several generations of new researchers in biological sciences.

Distribution and habitat. Rivulus berovidesi sp. n. is known only from northwest mountain system in Pinar del Rio province. Particularly, in Sierra de Cajalbana (type locality) and Rio Camarones. Both localities are situated in northwestern Cuba ( Fig. 1 ). This species inhabits small mountain streams with a depth of 30–70 cm approximately and bottom substrate basically composed by stones, sand and dead leaves ( Fig. 7 ). There is not aquatic vegetation in the area. The streams are clear with pH 7.5 and water temperature 24°C. Other freshwater fish collected together with Rivulus berovidesi sp. n. were: Gambusia punctata , Girardinus uninotatus , Girardinus creolus , Girardinus microdactylus , Nandopsis tetracanthus , Agonostomus monticola and Gobiomorus dormitor .

Figures

FIGURE 1. Distribution map of Rivulus species from Cuba. Red spots represent distribution of Rivulus cylindraceus and red triangles represents distribution of Rivulus berovidesi sp. n., 1 Sierra de Cajalbana (type locality); 2 Rio Camarones.

FIGURE 2. Outline drawings of the frontal scalation patterns of Rivulus from Cuba. A: Rivulus berovidesi sp. n. with a d - type pattern and B: Rivulus cylindraceus with an e - type pattern. The horizontal broken line indicates the pair of scales with their margins fully exposed.

FIGURE 3. Rivulus berovidesi sp. n., life coloration in both sexes in specimens kept in captivity for three months after collection in the field.

FIGURE 4. Rivulus berovidesi sp. n., life coloration in males (above) and females (below) in specimens just after collection in the field.

FIGURE 5. Rivulus berovidesi sp. n., paratype, female, CZACC- 9.85, 37.2 mm SL, small stream in Sierra de Cajalbana, Pinar del Rio province, Cuba.

FIGURE 6. Rivulus berovidesi sp. n., holotype, male, CZACC- 9.83, 37.3 mm SL, small stream in Sierra de Cajalbana, Pinar del Rio province, Cuba.

FIGURE 7. Type locality of Rivulus berovidesi sp. n. Small stream at Sierra de Cajalbana, Pinar del Rio province, Cuba

Tables

TABLE 1. Morphometric data for holotype and paratypes of Rivulus berovidesi sp. n. Standard length (SL) and head length (HL) are expressed in millimeters; all other measurements are expressed as percentage of SL except for eye diameter and snout length, which are given as percentage of HL.

	Holotype	N	Paratypes
Morphometric variables			Mean	Min Max	SD
Standard length (mm)	37.3	23	33.8	28.9 37.9	2.5
Pre-dorsal length	68.0	23	70.1	67.3 71.5	1.6
Pre-anal length	60.9	23	61.9	59.5 65.3	1.2
Interdorsal-anal length	7.1	23	8.2	6.8 10.6	1.1
Caudal peduncle depth	13.7	23	12.7	11.1 14.4	0.9
Head length (mm)	10.4	23	9.0	8.1 10.4	0.6
Snout length	28.1	23	30.1	25.9 33.5	2.0
Eye diameter	23.7	23	26.6	23.7 30.0	1.8