Larimichthys terengganui, Seah, Ying Giat, Hanafi, Norhafiz, Mazlan, Abd Ghaffar & Chao, Ning Labbish, 2015

Seah, Ying Giat, Hanafi, Norhafiz, Mazlan, Abd Ghaffar & Chao, Ning Labbish, 2015, A new species of Larimichthys from Terengganu, east coast of Peninsular Malaysia (Perciformes: Sciaenidae), Zootaxa 3956 (2), pp. 271-280 : 272-279

Larimichthys terengganui sp. nov.

( Figs. 1–4 , Table 1 )

Larimichthys crocea (non Richardson, 1846): Matsunuma et al., 2011:140.

Holotype. NMMB-P 21523, 1 (161mm SL), fish landing port at Pulau Kambing, Kuala Terengganu, Malaysia, collected by Norhafiz Hanafi in March 2014.

Paratypes. KAUM-I. 16977, 1 (200 mm SL), Kuala Terengganu, identified as Larimichthys crocea (photo on p. 140 in Matsunuma et al., (2011). NMMB-P 21723, 1 (166 mm SL), collected with holotype NMMB-P 21523, fish landing port at Pulau Kambing, Kuala Terengganu, Malaysia, collected by Norhafiz Hanafi in March 2014, (gas bladder and right side otolith extracted for illustration). NMMB-P 21542, 2 (151 & 155 mm SL), fish landing port at Pulau Kambing, Kuala Terengganu, Malaysia, collected by Norhafiz Hanafi, March 2014. NMMB-P 21524, 1 (161 mm SL), one of three from UMTF 0 5798, off Terengganu ( Matsunuma et al. 2011). UMTF 0 5949, 0 5950, 2 (171 & 178 mm SL), two of three from UMTF 0 5798, off Terengganu ( Matsunuma et al., 2011). UMTF 05951- 0 5956, 6 (153–173 mm SL), fish landing port at Pulau Kambing, Kuala Terengganu, Malaysia, collected by Norhafiz Hanafi, March 2014.

Diagnosis. A species of Larimichthys with an equally short pair of ventral and dorsal limbs at the lateral ends of gas bladder appendage; gill raker length about ½ the eye diameter, shorter than gill filament at the angle of first gill arch; snout length greater than eye diameter; 2nd anal spine equal or slightly shorter than eye diameter; outer gill rakers of first arch 22–25. Inner gill rakers of first arch 17–19. Vertebrae 11 + 13 = 24. Second dorsal fin soft rays 29–32.

Description. Counts and measurements of the type specimens are shown in Table 1 . The following data are provided for the holotype, followed by the size range and mean for the 13 paratypes.

Holotype Paratypes (n = 13) ......continued on the next page Holotype Paratypes (n = 13) Dorsal fin with IX spines on the anterior (spinous) portion and I spine and 29–32 soft rays on the posterior portion. Anal fin with II spines and 8 or 9 soft rays. Pectoral fin with 16–17 soft rays. Outer gill rakers of 1st arch 7– 9 + 15–17 = 22–25. Inner gill rakers of 1st arch 5–6 + 12–14 = 17–19. Preopercular margin weakly indented no sharp spines. Lateral line pore scales 49–54. Circumpeduncular scales 18–20. Vertebrae 11 + 13 = 24.

Gas bladder with 26 pairs of lateral appendages, including a couple of long branched appendages extended to the base of anal fin ( Fig. 2 ). A pair of equally short ventral limbs at the lateral ends of gas bladder appendage, which are not extend lateral-ventrally to lower half of the body wall ( Fig. 3 ).

Sagitta ( Fig. 4 ) kidney-shaped with a shallow tadpole-shaped sulcus mark on its inner surface, ostium (head) rounded, a shallowly grooved, cauda, and a conspicuous marginal groove dorsally; outer surface more elevated at posterior half.

Body fusiform, elongated with a moderately large head, about 3 times in standard length (SL). Head cavernous but moderately firm. Snout 4.1–4.6 in head length, its tip with three upper and five marginal pores; rostral fold slightly indented below the marginal pores. Eye moderately large, oval shaped, horizontal diameter 4.4–5.9 in head length. Interorbital region broad, 3.3–4.0 in head length. Preopercular margin weakly indented without sharp spines or serration.

Mouth large oblique, terminal, maxillary 1.8–2.1 in head length, the lower jaw slightly projecting, the mouth gape forming an angle of about 45 degrees. Tip of upper lip on horizontal passing near ventral margin of orbit. End of maxillary on vertical line passes near posterior margin of eye. Underside of lower jaw with 6 pores, the median pair set on tip of lower jaw.

Teeth narrow set in ridges, upper jaw with an outer row of clearly enlarged, conical teeth bordered medially by a narrow row of smaller teeth. Lower jaw with a row of enlarged sharp teeth, several larger teeth clustered at the tip of lower jaw.

Gill rakers, moderately long and slender, the longest one at the angle about ½ the eye diameter, shorter than gill filament at the angle of arch.

Anal fin truncate, the second spine short and fairly stout, 4.5–6.1 in head length. Caudal fin rhomboidal, about ⅔ of head length. Tip of pectoral fin vertically passed beyond the tip of pelvic fin but short of vent. Pelvic tip not filamentous, its distance to vent is greater than that of vent to anal fin origin.

Scales moderately large, thin and ctenoid on posterior half of body behind the tip of pectoral fin tip, ctenii on scales becoming reduced anteriorly, below first portion of dorsal fin and between pectoral and pelvic fins. Transverse scale between dorsal fin origin and lateral line 6–7. Dorsolateral scales above lateral line ctenoid. Head squamation completely cycloid, scales becoming reduced and embedded on the snout and suborbital region. Soft dorsal and anal covered with small cycloid scales from base to distal margin. Pectoral, pelvic and caudal fins, with small cycloid scales at bases, naked distally. Lateral line pored scales smooth anteriorly, but with a small field of ctenii posteriorly. Pored lateral line scales usually with a single dorsal and ventral branch, occasionally more arborescent.

Photophore perforated scales are also found on the belly, which are more prominent above anal fin base and extended to lower portion of caudal peduncle.

Color in alcohol. Ground color brownish darker dorsally and fading to whitish pale ventrally. Snout, top of head, nape, dorsum and sides above level of pectoral fin base profusely dusted with very small brown chromatophores, becoming larger and more widely dispersed ventrally, and disappearing from ventral body surface. Tip of snout with a darkish blotch, upper lip with a dark margin dorsally, lower lip with a dark margin, roof of mouth pale, becoming dusky posteriorly to dark lining in upper part of inner opercula chamber, appearing as a dark triangle externally. Eye with dark upper and lower margin, suborbital pale with scattered silvery tint. Spinous dorsal with dark tip, distal margin of soft dorsal dusky; pectoral fin axil with a black blotch. Pelvic and anal fin pale to yellowish. Caudal lightly and evenly dusted. Belly with photophores along scale rows, 4–5 prominent rows above anal base to lower part of caudal peduncle. Peritoneum variably sprinkled with large, stellate, chromatophores, especially in anterior portion of the body cavity.

Distribution. All know specimens of the species were collected from South China Sea around Kuala Terengganu, east coast of Peninsular Malaysia. The species may be endemic to the area.

Etymology. Named after the locality of the new species, Terengganu, east coast of Peninsular Malaysia.

Comparisons. Larimichthys terengganui can be distinguished from other species of the genus by having gas bladder appendages at ventral limb with a pair of equally short branches; both branches are elongate in L. crocea and only one is elongated anteriorly in L. polyactis . Although L. pamoides (specimens not examined) has a pair of short limbs ( Trewavas, 1977, Fig. 60), but other characters are distinct from L. terengganui ( Trewavas, 1977, p. 542), and as reported from northwestern Australia and southern New Guinea, appears to have a distribution separate from that of Larimichthys terengganui . Furthermore, L. pamoides is entirely covered in cycloid scales, unlike the other species which are mostly covered with ctenoid scales, with cycloid scales only on head and below pectoral fins. The new species has the least number of vertebrae (24), compared to the other species, 25 in L. crocea and L. pamoides , and 28 in L. polyactis . Larimichthys terengganui has fewer dorsal soft rays (29–32 vs. 31–36 in other Larimichthys ). Furthermore, the second anal spine in L. terengganui is equal or slightly shorter than eye diameter, but shorter in L. polyactis , longer in L. pamoides and equal or slightly longer in L. crocea . Larimichthys terengganui can be distinguished from L. crocea and L. polyactis by having a gill raker shorter than gill filament at the angle of first gill arch, and a relatively elongated anterior part of fish (head length 30.6–34.2% SL; snout to pectoral fin insertion 30.5– 32.2% SL; snout to pelvic fin insertion 33.0–35.9% SL). External morphology of L. terengganui is most similar to that of L. crocea , with a snout length greater than eye diameter, whereas in L. crocea the snout is shorter than eye diameter. Larimichthys terengganui has fewer gill rakers on the first arch than Larimichthys crocea (22–25 vs. 26– 28), and has fewer scales above lateral line than Larimichthys crocea (7–8 vs. 8–10). Diagnostic characters of the four species of Larimichthys are presented in Table 2 .

* Data from Trewavas (1977), for holotype of species.

Remarks. The species was first reported in Matsunuma et al. (2011:140) as a new record of Larimichthys crocea in east coast of Peninsular Malaysia. Three specimens were kept at the UMT fish collection. In March 2014, Mr Norhafiz Hanafi collected additional specimens and which were subsequently identified as a new species described herein.

Figures

FIGURE 1. Larimichthys terengganui sp. nov. (paratype: KAUM – I. 16977, 200 mm SL; identified as Larimichthyes crocea in Matsunuma et al. (2011: 140).

FIGURE 2. Gas Bladder of Larimichthys terengganui (paratype: NMMB-P 21723, 166 mm SL, female), with 26 pairs of lateral appendages and follow by a couple of long branched appendages extended to the base of anal fin. Dorsal view (top) and ventral view (bottom).

FIGURE 3. Close-up view of gas bladder for Larimichthys terengganui (paratype: NMMB-P 21723, 166 mm SL, Female), with an equally short pair of ventral limbs at the lateral end of gas bladder appendages. Dorsal view (top) and ventral view (bottom).

FIGURE 4. The right sagitta of Larimichthys terengganui, medial surface (A), lateral surface (B) and dorsal view (C), NMMB-P 21723, 166 mm SL, Female.

Tables

TABLE 1. Morphometric and meristic data of type specimen of Larimichthys terengganui sp. nov. in present study. SD = standard deviation.

	NMMB-P 21523	Min	Max	Mean	SD
Standard Length (mm)	161.0	151.1	197.8	165.8
Counts
1st dorsal fin spine	9	9	9	9.0	0.0
2nd dorsal fin spine	1	1	1	1.0	0.0
2nd dorsal fin soft rays	32	29	32	30.9	1.0
Anal fin spine	2	2	2	2.0	0.0
Anal fin soft rays	9	8	9	8.6	0.5
Pectoral fin rays	16	16	17	16.1	0.3
Outer gill rakers of 1st arch	23	22	25	23.6	1.2
upper limb	7	7	9	7.5	0.7
lower limb	16	15	17	16.1	0.7
Inner gill rakers of 1st arch	18	17	19	18.4	0.6
upper limb	6	5	6	5.4	0.5
lower limb	12	12	14	12.9	0.6
Lateral line pore scales	51	49	54	51.8	1.3
Scale rows in longitudinal series	58	56	62	57.6	1.9
Scales above lateral line	7	7	8	7.5	0.5
Scales below lateral line	8	7	9	8.1	0.5
Circumpeduncular scales	18	18	20	18.7	0.7
Vertebrae	24	24	24	24.0	0.0
precaudal	11	11	11	11.0	0.0
caudal	13	13	13	13.0	0.0
Measurements
Snout to anal fin origin	72.0	69.1	72.7	71.2	1.1
Snout to 2nd dorsal fin origin	51.5	47.6	51.6	50.4	1.0
Snout to 1st dorsal fin origin	32.5	32.0	34.2	33.0	0.7
Snout to pectoral fin insertion	31.2	30.5	32.2	31.3	0.5
Snout to pelvic fin insertion	35.3	33.0	35.9	34.2	1.0
Head length	32.8	30.6	34.2	32.5	0.8
Snout length	8.0	7.0	8.0	7.6	0.3
Maxilary length	16.9	15.1	17.7	16.6	0.7
Eye diameter	6.7	5.4	7.4	6.5	0.6
Interorbital width	9.4	7.9	9.5	8.9	0.4
Pectoral fin length	28.6	23.3	29.2	26.4	1.7
Pelvic fin length	21.1	18.0	21.3	19.5	1.1
Body depth (D1-P2)	28.9	27.6	30.2	29.3	0.7
Body width (P1-P1)	15.7	13.2	16.5	15.2	0.8

TABLE 2. Comparative counts and measurements of Larimichthys terengganui sp. nov. with similar species.

	L. terengganui	L. crocea	L. polyactis	L. pamoides *
SL (mm)	151–198	122–380	105–285	88
Number	14	8	12	1
Counts
2nd dorsal fin soft rays	29–32	31–35	32–36	36
Anal fin soft rays	8–9	8	8–10	7
Outer gill rakers of 1st arch	22–25	26–28	25–31	26
lower limb	15–17	18–20	16–21	18
Inner gill rakers of 1st arch	17–19	20–22	19–22	-
lower limb	12–14	14–16	13–16	-
Lateral line pore scales	49–54	49–56	54–59	-
Scale rows in longitudinal series	56–62	70–72	64–65	-
Scales above lateral line	7–8	8–10	5–8	-
Circumpeduncular scales	18–20	20–24	20–21	-
Vertebrae	24	25	28	25
precaudal	11	11	12–13	10
caudal	13	14	15–16	15
Measurements
as % of SL
Snout to 2nd dorsal fin origin	47.6–51.6	42.1–43.5	45.2–50.9	-
Snout to 1st dorsal fin origin	32.0–34.2	28.1–28.6	30.7–36.8	-
Snout to pectoral fin insertion	30.5–32.2	26.8–27.4	27.1–30.2	-
Snout to pelvic fin insertion	33.0–35.9	30.2–32.8	31.0–31.8	-
Head length	30.6–34.2	27.1–30.0	25.1–29.8	31.6
Snout length	7.0–8.0	5.6–6.7	5.3–7.3	8.9
Eye diameter	5.4–7.4	5.2–8.3	5.9–7.5	8.3
Interorbital width	7.9–9.5	7.6–9.1	7.3–8.9	10.6
Pectoral fin length	23.3–29.2	19.6–23.0	21.4–26.6	25.4
Body depth (D1–P2)	27.6–30.2	24.7–28.5	23.3–28.7	30.8
2nd dorsal fin base length	42.1–45.9	46.0–49.6	41.1–45.5	-
2nd anal spine length	5.1–7.1	4.8–8.4	4.3–6.7	10.7
Caudal peduncle depth	7.5–8.8	6.8–7.7	7.1–9.0	-
Longest gill raker on 1st arch	3.2–3.8	3.4–4.5	3.0–4.1	-
Longest gill filament on 1st arch	3.5–4.7	2.4–4.0	2.4–3.7	-