Calamiana taiwanensis, Chen & Shao & Huang, 2024

Calamiana taiwanensis sp. nov.

(ḁĝ克利*ṞĖ)

( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Material examined

Holotype.— NTOUP 2012-04-135 , 28.5 mm SL, male, estuary of the Zhuan River , Yilan, Taiwan, coll. Shih-Pin Huang, 15 January 2010.

Paratypes.— ASIZP0081789 , 1 specimen, 27.9 mm SL, female, estuary of the Lanyang River , Yilan, Taiwan, coll. S.-P. Huang, 15 February 2012 . NTOUP 2012-04-136 , 1 specimen, 28.1 mm SL, estuary of the Zhuan River , Yilan, Taiwan, coll. S.-P. Huang, 15 January 2009 . NTOUP 2012-04-137 , 3 specimens, 21.3–30.8 mm SL, estuary of the Zhuan River , Yilan, Taiwan, coll. S.-P. Huang and H.-M. Huang, 1 February 2013 . NTOUP 2012-04-139 , 1 specimen, 32.8 mm SL, estuary of the Zhuan River , Yilan, Taiwan, coll. S.-P. Huang, 15 July 2010 .

Non-types: NTOUP 2012-04-138, 4 specimens, 13.7–19.2 mm SL, collected with NTOUP 2012-04-137. NTOUP 2012-04-134, 1 specimen, 32.5 mm SL, estuary of the Zhuan River , Yilan, Taiwan, coll. S.-P. Huang and H.-M. Huang, 15 July 2010 .

Diagnosis. Calamiana taiwanensis sp. nov. can be distinguished from congeners by the combination of features: (1) fin rays: D2 I/7–8 (modally 8), A I/7–8 (modally 8), P 16–18, and first dorsal fin triangular, second to third spines filamentous in adult males; (2) squamation: longitudinal scales 34–36 (modally 35), predorsal scales 16–18 (modally 17); (3) specific coloration: four distinct stripes on the cheek and preopercular regions, caudal fin base with two black spots, caudal fin membrane with 5–11 vertically-aligned lines; and (4) specific head pore pattern: anterior termination with a pair of pores σ and λ, median interorbital region with a pair of pores κ1 and κ, postorbital region with a pair of pores ω, lateral termination with a pair of pores α, upper margin of preopercular region with a pair of pores β and ρ.

Description. Body elongated, sub-cylindrical anteriorly and compressed posteriorly. Head large. Upper lip more prominent than lower lip when closed. Eyes moderately large and placed dorsolaterally on head. Mouth maxillary extending to the vertical of anterior margin of pupil in adult males, and only reaching anterior margin of orbit in females. Anterior nares as short tube, posterior nares as round hole. Gill slit restricted, extending ventrally slightly beyond the middle vertical line of operculum. Vertebral counts 26 (10+16) (in 8 individuals) ( Table 1 View TABLE 1 ).

Teeth in males slightly longer than in females. Upper jaw with two rows of stout small teeth, anterior teeth obviously longer than the laterals; lateral teeth nearly even in size. Anterior region of lower jaw with three rows of teeth; two rows of teeth laterally; outermost teeth slightly curved and larger.

Fins. D1 VI; D2 I/7–8 (modally 8); A I/7–8 (modally 8); P 16–18 ( Table 2 View TABLE 2 ). First dorsal fin triangular, second to third spines usually filamentous in adult males, but rounded and lacking any filamentous rays in females. Anal fin inserted below first branched rays of second dorsal fin. Pelvic fin rounded. Caudal fin oval-shaped and rear margin rounded.

Scales. LR 34–36 (modally 35); TR 12–13 (modally 12); PreD 16–18 (modally 17); SDP 11–12 (modally 11) ( Table 2 View TABLE 2 ). Body covered with moderate-sized ctenoid scales. Predorsal region and belly covered with moderate-sized cycloid scales. Opercular region covered with small cycloid scales. Cheek naked.

Head lateral-line system: head canals. Anterior oculoscapular canal present, interior termination with a pair of pores σ and λ, median interorbital region with a pair of pores κ1 and κ, postorbital region with a pair of pores ω, lateral termination with a pair of pores α, upper margin of preopercular region with a pair of pores β and ρ.

Head lateral-line system: sensory papillae. Row a short, about two-thirds of orbit diameter. Row b short, with densely-set papillae, starting from vertical of rear margin of pupil. Single c papilla. Row cp short, extending to posterior region of orbit. Row d long and with densely-set papillae. Opercular region with rows os, oi and ot. Rows oi and ot slightly separated. Row f consists of a pair of papillae.

Osteological features. Top of cranium always smooth and flat, lacking elevated ridge (Fig. 6A). Pterygiophore formula is 3-12210 (Fig. 6B). Caudal skeleton with hypurals 1 and 2, hypurals 3 and 4, hypural 5, a pair of epurals and single parhypural (Fig. 6C); the hypurals 1 and 2, and hypurals 3 and 4 fused together, respectively. Anterior epural bar-shaped, the posterior epural triangular, the parhypural needle-like. Jaws and suspensorium (Fig. 6D); maxilla stout and short; ectopterygoid stout, short and triangular. Upper jaw with two rows of teeth. Anterior process of premaxilla tall, and posterior portion distinctly prominent. Palatine slightly stout, and lower margin not in touch with quadrate. Metapterygoid rectangular. Posterior portion of dentary tall, with a square tip. Anguloarticular at upper tip longer than the lower. Quadrate joining anguloarticular and ectopterygoid along anterior margin, joining symplectic at posterior margin, joining metapterygoid at upper margin, and preopercle at lower margin. Hyomandibula joining metapterygoid at anterior margin, and joining preopercle at posterior margin. Preopercle L-shaped, anterior tip elongated and sharp. Interopercle elongate and anterior tip pointed.

Coloration in fresh specimen. Head and body generally creamy yellow or brownish yellow, body with numerous short brownish red bars in adult males, but usually black in females. Lateral scales with blackish brown margin. Belly creamy white. Cheek and preopercular regions with four distinct oblique brownish red or black stripes. A black stripe starting from anterior region of orbit and extending forward to snout tip. First dorsal fin with 5–6 rows of longitudinally-aligned brownish red lines in adult males, and 3–4 rows of longitudinally-aligned brown lines in females. Second dorsal fin with 4–5 rows of longitudinally-aligned brownish red lines. Upper region of pectoral fin base with a blackish brown blotch. Caudal fin base with two vertically aligned blackish brown bars. Pelvic fin grayish black in adult males, but grayish white in females. Anal fin pale orange in adult males, but grayish white in females. Caudal fin pale brownish red in adult males and grayish white in females; caudal fin membrane with 5–11 rows of vertically-aligned reddish brown or brown lines.

Distribution. So far, this new species is known only from brackish water habitats of northern Taiwan ( Fig. 1 View FIGURE 1 ).

Etymology. The specific name, taiwanensis , refers to the locality “ Taiwan ” where the new species is found.

Remarks. Compared to all valid species of the genus Calamiana , firstly, C. taiwanensis sp. nov. can be distinguished from C. mindora by the following features: (1) different head pore patterns: this new species has a complex head pore pattern, including pores σ and λ, median interorbital region with a pair of pores κ1 and κ, postorbital region with a pair of pores ω, lateral termination with a pair of pores α, preopercular region with a pair of pores β and ρ. However, the holotype of C. mindora lacks head pores, and only Fijian specimens possess a few head pores ω, α and β, restricted to the postorbital region; (2) different osteological features: in this new species, the posterior part of the premaxilla has a distinct prominence (Fig. 6D) and the interopercle is narrow, whereas C. mindora has only a smooth rounded dorsal edge of the premaxilla and a wider interopercle with pointed tip; (3) cheek with four distinct curved oblique broad stripes in this new species, while 2–3 lines present on cheek and other lines broken or diffuse in C. mindora ; and (4) this new species usually has more anal fin rays when compared to C. mindora (modally I/8 vs. I/7).

Additionally, this new species can be distinguished from C. illota by the following features: (1) first dorsal fin triangular, with second to third spines filamentous in adult males vs. first dorsal fin triangular to slightly rounded and spines occasionally filamentous; and (2) a pair of median interorbital pores κ1 and κ vs. single pore κ and pore κ1 absent. Finally, C. taiwanensis n. sp. can be separated from C. variegata by the following features: (1) first dorsal fin triangular, and second to third spines filamentous in adult males vs. first dorsal fin rounded and spines never filamentous; (2) a pair of median interorbital pores κ1 and κ vs. single pore κ and pore κ1 absent; (3) four stripes on the cheek and preopercular regions vs. two stripes on the cheek; and (4) more longitudinal scales, 34–36 vs. 30–32.