Hypsolebias faouri, Britzke, Ricardo, Nielsen, Dalton T. B. & Oliveira, Claudio, 2016

Britzke, Ricardo, Nielsen, Dalton T. B. & Oliveira, Claudio, 2016, Description of two new species of annual fishes of the Hypsolebias antenori species group (Cyprinodontiformes: Rivulidae), from Northeast Brazil, Zootaxa 4114 (2), pp. 123-138 : 125-128

Hypsolebias faouri , new species

( Figs.1 and 2 , Table 1 )

Hypsolebias aff. igneus . Ponzetto et al., 2016.

Holotype. ZUEC 10796, 0 1 male 43.6mm SL: Brazil, Bahia, Prazeres, Rio Preto, Rio São Francisco basin, 11º23’24.8”S 44º54’11.2”W, altitude 522 m, 25 January 2014. Col. Mayler Martins, Amer Faour, Fabio Origuela de Lira & Luciano Medeiros de Araújo.

Paratypes. ZUEC 10797, 0 3 males 43.8-44.6 mm SL, 0 5 females 36.4–39.5mm SL. LBP 18842, 0 1 males 43.1 mm SL, 0 1 female 38.2 mm SL. Same date as holotype.

Diagnosis. Males of Hypsolebias faouri differs from the remaining species of the Hypsolebias antenori species group by possessing a lower head depth (77.3–82.7% HL vs. 97.1–108.7% in H. janaubensis and 106.9–121.1% in H. mediopapillatus ), smaller eye diameter (21.8–22.9% HL vs. 24.7–30.2% in H. ghisolfii and 35.2% in H. radiseriatus ), eight pelvic-fin rays (vs. six or seven in H. igneus ), shorter caudal-fin length (27.1–30.5% SL vs. 33.1–35.8% in H. antenori and 36.9–43.2% in H. pterophyllus ).

It is distinguished from all other species of the Hypsolebias antenori species group by: the presence of inconspicuous bars on flank in live males, visible in preserved specimens, except H. igneus (vs. bars visible in live and preserved specimens); by possessing a unique anal-fin color pattern in males, with anterior two thirds orange and posterior portion yellow, with bluish white dots, blue spot on tip, black distal strip, except in H. igneus , H. antenori and H. coamazonicus (vs. yellow in H. ghisolfii , and pink anteriorly and yellow posteriorly in species of the H. flavicaudatus complex and H. flagellatus ); presence of inconspicuous bars on flank in live males, visible in preserved specimens, except H. igneus (vs. bars visible in live and preserved specimens); and by shorter dorsal-fin length, except H. guanambi , (33.6–36.5% SL vs. 38.9–45.3 %).

In addition, males of H. faouri can be distinguished from H. martinsi by: longer lower jaw length (27.3–31.1% HL vs. 22.8–25.4% HL), smaller eye diameter (21.8–22.9% HL vs. 28.1–33.4 HL), having higher body depth (37.8–42.9% SL vs. 34.1–27.4% SL), greater number of scales in longitudinal series (30–32 vs. 27–28), greater number of scales in transversal series (14 vs. 12), body with blue iridescent spots (vs. absent), longer prepelvic length (47.2–49.3% SL vs. 41.9–43.5% SL), greater number of dorsal-fin rays (22–23 vs. 20), greater number of caudal-fin rays (24–25 vs. 20–21), greater number of anal-fin rays (24 vs. 20), greater number of pectoral-fin rays (14 vs. 13), unpaired fins with blue iridescent large spots (vs. absent), and long filaments in anal and dorsal fins (vs. short) in males. Females of H. faouri differ from remaining species of the Hypsolebias antenori species group by: lower head depth (77.7–86.1% HL vs. 88.6–100.1% in H. janaubensis and 101.6–125.7% in H. mediopapillatus ), smaller head width (54.7–58.6 % HL vs. 62.5–72.2 in H. janaubensis and 69.6–82.5% in H. ghisolfii ), and shorter caudal-fin length (28.6–31.0% SL vs. 32.3–36.8% in H. janaubensis and 34.4–38.8% in H. sertanejo ). Females of H. faouri can be distinguished from H. martinsi by longer lower jaw length (27.7–26.4 vs. 21.4–24.5), having shorter prepelvic length (42.2–45.8% SL vs. 47.7–52.1% SL), and greater number of anal-fin rays (22 vs. 20).

Description. Morphometric data presented in Table 1 . Largest specimen examined 44.6 mm SL. Body relatively deep, compressed, greatest body depth at level of pelvic fin base. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females. Dorsal profile slightly concave on head, convex from nape to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to the end of anal fin base, nearly straight on caudal peduncle. Eyes positioned on upper portion of side of the head. Tip of dorsal and anal fin pointed with filaments in males and rounded to slightly pointed in females. Tip of both dorsal and anal fins with filamentous rays in males, sometimes reaching vertical through posterior portion of caudal fin, 2–3 filaments in dorsal-fin and 1–3 filaments in anal-fin; filaments absent in females.

Dorsal and anal fin rays unbranched in males and females. Caudal fin subtruncated in both sexes. Pectoral-fin elliptical. Posterior margin of each pectoral fin reaching vertical through base of third or fourth anal-fin ray in males, and between pelvic fin and first and second in females. Tip of each pelvic fin reaching base of 2nd anal-fin ray in males and 1st in females. Pelvic-fin separated by small interspace.

Dorsal-fin origin in vertical through same origin of anal-fin ray in males, and base of 8th anal-fin ray in females; dorsal-fin origin between neural spines of vertebra 8 in males and neural spines of vertebra 12 in females. Anal fin origin at 8th pleural rib of vertebrae in males, and pleural ribs of vertebra 26 in females. Dorsal-fin rays 21– 22 in males, 15 in females, anal-fin rays 24 in males, 22 in females, caudal-fin rays 24–25, pectoral-fin rays 14, pelvic-fin rays 8.

Frontal squamation E-patterned; E-scales overlapping medially; no scales anterior to H-scale. Longitudinal series of scales 30–32; transverse series of scales 12–14; scale rows around caudal peduncle 17.

Contact organs absent. Cephalic neuromasts: supraorbital 14–16, parietal 3, anterior rostral 1, posterior rostral with one lateral neuromast and one middle neuromast, infraorbital 2 + 20–23, preorbital 3, otic 1–2, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 16–18, mandibular 12–14, lateral mandibular 4, and paramandibular 1. One neuromast on each scale of lateral line. Two neuromasts on caudal-fin base. Total vertebrae 26.

Coloration in life. Males: Sides of body light gray, with light small bluish dots. Body bars conspicuous in adult, but in preserved fishes with 9–11, narrow, straight faint gray bars on flank. Dorsum light orange. Venter pale orange. Opercular region light metallic greenish. Iris light yellow, with dark gray bar. Dorsal fin reddish on distal area and yellow on anterior portion, with blue dots; dorsal-fin with 2–3 black filaments. Anal fin yellow, with small blue dots, subdistal zone dark orange, black distal stripe, small metallic blue stripe between yellow and black zones; anal-fin with 2–3 black filaments. Caudal-fin yellow with light bluish dots and distal bluish stripe. Pectoral fins hyaline. Pelvic fins orange with distal black stripe.

Females: Sides of body light gray, with 12 gray bars; venter pale orange; 2–3 rounded black spots on anterocentral portion of flank; one irregularly arranged rounded black blotch on caudal peduncle. Iris light yellow, with gray bar through center of eye. Unpaired fins hyaline.

Distribution ( Fig. 5 ). Known only from the type-locality.

Habitat ( Fig. 3 ). Typical annual pool in Caatinga biome, located about 96 km to the north of the city of Barreiras. The substrate is composed of clay and sand with slightly dark water. Aquatic vegetation is dense with a lot of Echinodorus sp. and Nymphea sp. Average depth of the pool is 100 cm, with deepest portions about 130 cm, with pH 6.5 and low electric conductivity (18µS). The temperature on the water surface was approximately 28º C and, in the deepest portion and banks, approximately 25º C. The region’s annual average temperature is 28º C, with maximum of 34º C and minimum of 20º C. The rainy season occurs from December to March. Sometimes the “Veranico” (Indian Summer) occurs, a phenomenon which consists of a dry period with high temperatures inside rainy seasons ( Nielsen, 2008). Hypsolebias faouri was found with Astronotus ocellatus and Oreochromis niloticus . The pool is next to the road, near simple houses. The population living in these residences keep O. niloticus and A. ocellatus in the pool as a means of having an alternative source of protein. One side of the pool was excavated for preserving the water throughout the year, so a part of the pool does not dry which explains the survival of introduced species.

Behavior in captivity. Hypsolebias faouri follows the same pattern of behavior of other Hypsolebias species. The male is territorial, but is not aggressive, females that enter their territory promote the mating ritual. The male begins courtship display with waving motions of the body, while moving around in front of the female. The male places its snout in the region of the substratum where it wishes to dig. The female accepts the invitation and slides alongside the male, whereupon both dig into the substrate with waving vibrations of the body. They submerge into the substrate, where the female lays an egg. At that exact moment, the male presses the female against the substrate with his body and fertilizes her. After fecundation, the couple remains submerged for some seconds to a few minutes, emerging together or not at different places and times ( Belote, 2000).

Etymology. The species is named in honor and recognition to the first discoverer of the new species, the environmentalist Mr. Amer Faour.

Figures

FIGURE 1. Hypsolebias faouri, ZUEC 10796, male, holotype, 43.6 mm SL: Brazil, Bahia, Prazeres, Rio Preto, São Francisco basin. Photo by Dalton Nielsen.

FIGURE 2. Hypsolebias faouri, ZUEC 10797, female, paratype, 37.5 mm SL: Brazil, Bahia, Prazeres, Rio Preto, São Francisco basin. Photo by Dalton Nielsen.

FIGURE 3. Type locality of Hypsolebias faouri, Brazil, Bahia, Prazeres, Rio Preto, São Francisco basin. Photo by Amer Faour.

FIGURE 5. Map of northeastern Brazil showing known localities for species of the Hypsolebias antenori species group.

Tables

TABLE 1. Morphometric and meristic data for the holotype (H) and paratypes (P) of Hypsolebias faouri and Hypsolebias martinsi.

	Hypsolebias	faouri		Hypsolebias	martinsi
	Holotype	Paratype		Holotype	Paratype
	Male	Male n=3	Female n=5	Male	Male n= 2	Female n=4
Standard length (mm)	43.6	43.1–44.6	36.4–39.5	27.5	24.8–34.2	26.4–29.3
Percents of standard length
Body depth	38.0	37.8–42.9	35.9–37.9	37.4	34.1–37.4	31.4–36.3
Caudal peduncle depth	14.4	14.4–16.2	13.3–14.6	13.8	13.3–13.8	12.8–14.5
Pre-dorsal length	50.9	47.7–50.9	58.2–60.7	52.7	52.5–52.7	56.0–60.2
Pre-pelvic length	44.9	44.7–46.6	50.3–52.1	43.5	41.9–43.5	47.7–52.1
Length of dorsal-fin base	34.1	33.6–36.5	20.0–25.8	37.4	34.6–36.8	22.0–24.4
Length of anal-fin base	37.6	37.6–43.6	28.1–31.4	35.6	35.3–38.6	24.1–29.5
Caudal-fin length	28.2	27.1–30.5	28.6–31.0	23.4	23.4–27.2	26.7–30.3
Pectoral-fin length	25.4	24.6–28.3	22.0–26.6	27.4	27.4–31.2	19.2–23.8
Pelvic-fin length	9.8	8.9–11.3	9.8–11.9	9.8	9.8–11.7	11.2–12.4
Head length	30.5	29.9–30.8	29.9–33.2	29.1	29.1–30.2	31.8–36.3
Percents of head length
Head depth	84.9	77.3–84.9	73.7–86.1	86.6	86.6–90.6	78.1–83.1
Head width	70.6	66.3–70.6	54.7–58.6	55.1	54.0–56.6	56.9–58.2
Snout length	13.6	12.8–14.6	11.8–13.6	12.3	11.8–13.5	12.1–13.4
Lower jaw length	30.9	27.3–31.1	27.7–28.4	22.8	22.8–25.4	21.4–24.5
Eye diameter	21.8	21.8–22.9	21.6–26.4	32.5	28.1–33.4	22.9–24.6