Cryptocentrus taiwanensis, Chen & Yang, 2024

Cryptocentrus taiwanensis n. sp.

(Îĝẫǻ)

( Figs.1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 , 5)

Material examined

Holotype.— NTOUP-2024-09-255, 71.8 mm SL, Longdong Bay , Gong-Liao District, New Taipei City, Taiwan, ROC; 7–9 m depth; Coll. Y.C. Yang; Spt. 29, 2024.

Paratypes.— NTOUP-2024-09-256, 2 specimens, 60.4–63.0 mm SL, collection date and other data same as holotype .

Diagnosis

Cryptocentrus taiwanensis n. sp. can be well distinguished from all other congeners by the unique combination of the following features: (1) fins: second dorsal fin rays I/11; anal fin rays I/10; pectoral fin rays 16; (2) squamation: longitudinal scale series 100–101, transverse scale rows 29–31, no perdorsal scale; (3) normal vertebral count 26; (4) head canal pores: anterior oculoscapular canal with terminal pore σ; single pore λ; lateral section of anterior oculoscapular canal with three pores α, β and ρ. posterior oculoscapular canal with two pores θ and τ; preopercular canal present with three pores γ, δ and ε. papillae: 5 major transverse rows of infraorbital region; (4) rear edge of mouth: extending beyond the vertical of rear margin of pupil and (5) specific colouration: body scattered with many white spots and a middle longitudinal row of 8 blackish brown blotches, second dorsal fin with vertical blackish brown bars on branched rays on distal half, anal fin with three horizontal rows of blackish brown blotches and connected to stripe in middle row, caudal fin translucent radiating with thick blackish stripes in middle 1/3 region in male.

Description

Body proportions are listed in Table 1 View TABLE 1 . Body rather slender, subcylindrical anteriorly, compressed posteriorly. Head subcylindrical and somewhat compressed. Snout profile somewhat straight but steeply oblique. Cheek slightly fleshy in male. Lips thick. Eye relatively high and somewhat small. Eye diameter somewhat smaller than snout length. Outer profile of eye above dorsal-profile projection. Tongue margin rounded. rear edge of mouth: extending beyond the vertical of rear margin of pupil. Anterior nostril at end of short tube, projecting downward just behind upper margin of upper lip. Posterior nostril as an oblong pore anterior to lower part of eye. Postorbital range rather long. Upper jaw extending to a point beyond the rear margin of pupil. Gill-opening extending ventrally to about vertical of midline of opercle. Vertebral count 10+16=26 (n=3).

Fins.— D1 VI, D2 I/11; A I/10; P 16; V I/5+I/5 (as in Table 2 View TABLE 2 ). D1 rounded, all anterior 5 spinous rays about equal. Origin of A inserted below about third branched rays of D2. Rear tips of D2 and A fin rays almost not extending to procurrent rays of C in both sexes. P moderate moderate large and oblong, rear tip merely reaching about vertical line of last spinous rays in male. V moderate size and rounded, the distal franum margin rather straight. C elliptical and middle extension somewhat pointed.

Scales.— Body mostly covered with rather small cycloid scales, predorsal area entirely naked. LR 100–101; TR 29–31; Pred 15–17; and SDP 15 (as in Table 2 View TABLE 2 ). Head and prepelvic region entirely naked.

Head lateral line system ( Fig. 2 View FIGURE 2 )

Canals: Nasal extension of anterior oculoscapular canal with terminal pore σ located in above posterior nostrils. Anterior interorbital sections of oculoscapular canal with a single pore λ. A single pore κ in near rear of interorbital region and with paired pore ω. Lateral section of anterior oculoscapular canal with the front pore α, median pore β, and posterior terminal pore ρ. Posterior oculoscapular canal with two terminal pores θ and τ. Preopercular canal present with three pores including pore γ, δ and ε.

Sensory papillae: Typically cheek with transverse infraorbital papillae pattern. 5 major transverse rows of papillae below eye. In the middle crossing with very long row b starting from midline vertical of eye to corner of preopercule. Row d as the ventrally terminal points of all 5 transverse rows. Row 1 simple transverse. Row 2 mainly located below the longitudinal mid-line as row b. Row 3 long and crossing the row b. Row 4i mostly as linear transverse row below row b but only one side interrupted into two rows seen in left side of holotype (seen in Fig. 2 View FIGURE 2 ). Row 5 only seen as 5s as all papillae above row b. Row f as paired longitudinal row. Anterior edge of row oi connecting to lower region of row ot.

Coloration while fresh ( Figs.3 View FIGURE 3 , 5)

Head and body almost brown to blackish brown. Head with minute rounded white spots on lower half in male, and the spots on entirely lateral side in female. Body scattered with many small rounded white spots and a middle longitudinal row of 8 oblong blackish brown blotches. Dorsal view of head and body with a broad light brown band. Caudal fin base with two rounded browns spots.

First dorsal fin translucent with two somewhat horizontal rows of blackish brown blotches on dorsal half and a row of rounded brown spots on basal half.

Second dorsal fin translucent with vertical blackish brown bars on branched rays on dorsal half and 2 main horizontal rows of small brown spots on basal 1/3 region in male; it with 5–6 large oblique blackish brown blotches on dorsal half and 2 main horizontal rows of small brown spots on basal 1/3 region in female.

Anal fin translucent with three major horizontal rows of blackish brown blotches or connected to stripe in middle row in male; the three rows somewhat oblique in female. Pectoral fin translucent brown, with almost entirely scattered 8–9 vertical rows of brown dots. Pectoral fin base brown background scattered with several minute round white spots and an upper somewhat triangular, large creamy white mark. Pelvic fin pale white to snow white back ground; blackish brown in basal half and following with two transverse brown bands on distal region and narrow outer snow white margin in male; it scattered with several brown blotches in some smaller female. Caudal fin translucent radiating with thick blackish stripes which interrupted into 2 sections on upper and lower 1/3 region in male; it scattered with three main vertical rows of brown blotches in smaller female. Urogenital papilla pale, with melanophores on basal region.

Etymology

The specific name, taiwanensis , is referred to the type locality of current goby merely found from coastal waters of Taiwan.

Distribution

The new species is very rare and only found from coastal waters of coral-reef or reef in New Taipei City, Taiwan. It is still possible to be found in other locality of eastern Taiwan after more intensive survey for further field exploration.

Remarks

Although the new species Cryptocentrus taiwanensis n. sp. is rather similar to C. albidorsus than any other 6 nominal species grouping as the so-called “ Cryptocentrus leucostictus ” group defined by Hoese and Larson (2004) (due to seniority among 7 nominal species, it had better to call Cryptocentrus niveatus group defined for such 7 related slender species). If can be well separated from both two nominal species: C. malidiensis and C. nigrocellatus by (1) second dorsal fin rays I/11 vs. modally I/10; (2) anal fin rays I/10 vs. modally I/9. It can be separated from C. niveatus by rather different caudal and anal fin dark mark as well as pigmentation patterns. It can be also differentiated from C. liolepis by pectoral fin rays 16 vs. 18. It can be well separated from C. leucostictus by (1) lacking any distinct head oblique stripes vs. three conspicuous head dark oblique stripes and (2) different caudal fin marks. It can be also differentiated from C. maudae by (1) a horizontal row of 8 blackish brown blotches on lateral side vs. none of the pattern seen in lateral side; and (2) very different caudal fin pattern.

Therefore, the new species Cryptocentrus taiwanensis n. sp. can be well distinguished from the most close related species C. albidorsus among this slender group by the following features: (1) pectoral fin rays 16 vs. modally 17; (2) transverse scale rows 29–31 vs. 33–37; (3) predorsal scales 15–17 vs. predorsal region entirely naked; (4) lateral botches: 8 oblong or rounded blackish brown blotches vs. at least anterior 4–5 marks as small thin horizontal bars or small dots and posterior 3–4 remaining ones getting larger; (5) anal fin pattern: three major horizontal brown stripes in male vs. four series of rather oblique arranged spots in male; and (6) pelvic fin: a narrow distal snow white margin in male vs. about posterior half entirely pale white in male.

The unpublished mtDNA COI data form YCY (Yang, unpublished data) can also provide the solid evidence as the great mitogenetic differentiation from the two conspicuous, morphological discrete species in Taiwanese waters. Furthermore, the detailed molecular phylogenetic analysis for whole Taiwanese species of Cryptocentrus is still in progress for gathering the better or full pictures of speciation of local species.