Owstonia whiteheadi (Talwar)

Smith-Vaniz, William F. & Johnson, David, 2016, Hidden diversity in deep-water bandfishes: review of Owstonia with descriptions of twenty-one new species (Teleostei: Cepolidae: Owstoniinae), Zootaxa 4187 (1), pp. 1-103 : 95-96

Owstonia whiteheadi (Talwar)

( Figures 86 , 87 )

Sphenanthias whiteheadi Talwar, 1973:87 , fig. 1 (original description; off Quilon, India, about 9°N, 76°E; depth 300 m); Bineesh et al., 2011:64 , figs. 2‒4 (redescription of Sphenanthias whiteheadi ).

Owstonia whiteheadi Manilo and Bogorodsky, 2003 :S112 (in list of Arabian Sea coastal fishes).

Material examined. 2 specimens, 144‒158 mm SL: SAIAB 97707 (1, 157.5) and USNM 410300 (1, 144), India, SW coast near Quilon (Kerala), trawled in ca. 220‒ 350 m .

Diagnosis. A species of Owstonia with LL pattern 3; dorsal fin IV, 21‒23; anal fin I, 15–16; oblique body scale rows in mid-lateral series 39‒41; adults with teeth in outer row of each premaxilla 39–45; adults with depressed pelvic fin extending to anal-fin soft rays 4‒15, depending on sex of specimen.

Description. (Includes data of Talwar, 1972 and Bineesh et al., 2011.) A species of Owstonia with LL pattern 3, consisting of a simple lateral line that originates from posttemporal sensory canal near anterodorsal margin of gill opening, curves upward and backward then continues posteriorly just below dorsal-fin base to soft rays 18–23. Dorsal fin IV, 21–23; anal fin I, 15–16; pectoral fin 19–20; gill rakers 18–21 + 34–39 = 52–60. Vertebrae: precaudal 11, caudal 18, total 29; anal-fin pterygiophores anterior to 1st haemal spine 2. Oblique body scale rows in mid-lateral series about 39–41; nape scaly and cheek scale rows 3. Lower limb margin of preopercle with 7–11 moderate to strong spines. Papillae in slight depression behind tip of premaxillary ascending processes 4, arranged in 2 almost equally spaced pairs. Teeth in outer row of each premaxilla 39‒45, no inner teeth anteriorly. Teeth in lateral row of each dentary 21–26; symphyseal teeth 5‒6, relatively small, short, and spike-like, other dentary teeth conical with pointed tips, and with 0‒1 very small inner tooth anteriorly. Pelvic fin sexually dimorphic, depressed pelvic fin extending to anal-fin soft rays 4‒5 (females) and soft rays 14‒15 (males). Caudal fin lanceolate. In 7 specimens 140‒255 mm SL (including data from Bineesh et al., 2011), caudal fin 1.5‒2.0 times in SL; head 3.1‒3.8 times in SL; body depth at anal-fin origin 4.0‒5.0 times in SL.

Color pattern in alcohol: Adults with dorsal fin uniformly pale; membrane connecting maxilla and premaxilla with prominent black stripe extending to near anterior end of premaxilla, and inner membrane covering posterior part of dentary also black. In life, body and fins mostly crimson (distal third to half of dorsal and anal fins of some females may be orange-yellow) except for black premaxillary stripe and white elongate outermost pelvic-fin ray in large males.

Proportions of 2 specimens 144‒158 mm SL (also pelvic fin measurements of Talwar, 1972 and Bineesh et al., 2011 for 6 females 144‒240 mm SL and 5 males 140–255 mm SL), as percentages of SL: predorsal length 23.9‒24.8; preanal length 47.8‒53.8; dorsal-fin base 64.5‒68.7; anal-fin base 31.9‒36.2; pelvic-fin length 24.7– 35.7 (females) and 39.8‒55.6 (males); caudal-fin length 48.8‒65.4; body depth at anal-fin origin 23.4‒24.8; head length 29.5‒30.1; upper jaw length 13.6‒14.7; upper jaw depth 6.5‒7.1; orbit diameter 10.0‒11.2. As percentages of head length: upper jaw length 45.0‒49.8; orbit diameter 33.3‒38.0.

Comparisons. Owstonia whiteheadi is the only Indian Ocean species with IV dorsal-fin spines. Owstonia whiteheadi superficially resembles O. weberi but in addition to a different lateral-line pattern, O. weberi has fewer dorsal-fin spines III (vs. IV), anal-fin soft rays 13–14 (vs. 15–16) and adults with teeth in outer row of each premaxilla 15–21 (vs. 39–45). Other congeners with IV dorsal-fin spines differ (values for O. whiteheadi in parentheses) as follows: O. fallax and O. hastata have anal-fin ray counts of I, 16‒17 or II, 14 (vs. I, 15–16), fewer total gill rakers 40–46 (vs. 52–60) and precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 13 and 5 respectively (vs. 11 and 2); O. sibogae has fewer oblique body scale rows in mid-lateral series 27–29 (vs. 39–41), larger cheek scales, in 3 rows (vs. 4–5), and more precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 12 and 4 respectively (vs. 11 and 2); O. macrophthalma has more anal-fin soft rays 17–18 (vs.15–16), more anal-fin pterygiophores anterior to 1st haemal spine 3 (vs. 2), and fewer total gill rakers 49–50 (vs. 52–60). Owstonia contodon differs in having more anal-fin rays II, 16 (vs. I, 15–16), oblique body scale rows in mid-lateral series ca. 48–53 (vs. 39–41), and anal-fin pterygiophores anterior to 1st haemal spine 3 (vs. 2).

Etymology. Named for the British ichthyologist Peter J. P. Whitehead (1930‒1992); see Howes (1997) for a particularly interesting obituary of this enigmatic and productive biologist.

Distribution. ( Fig. 27 ) Known only from off the southern tip of India in the Gulf of Mannar where taken by shrimp trawlers in 220‒ 350 m.

Remarks. Talwar (1973) and Bineesh et al. (2011) both documented sexual dimorphism of pelvic fins in O. whiteheadi , with the depressed fins extending beyond anal-fin origin in both sexes and to anal-fin soft rays 14 or 15 in large males. According to Eschmeyer et al. (2016), the holotype of Sphenanthias whiteheadi (ZSI F6276/2) is deposited in the Zoological Survey of India collection in Kolkata.

Figures

FIGURE 27. Distributions of selected species of Owstonia based on specimens examined.

FIGURE 86. Owstonia whiteheadi, male, size not specified, India. Photograph by M. Hashim, after Bineesh et al., 2011, fig. 2.

FIGURE 87. Owstonia whiteheadi, female, 150 mm SL, India. Photograph by K. K. Bineesh, CMFRI.