Comprehensive Description

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Acanthopagrus taiwanensisn. sp.

New English Name: Taiwan Picnic Seabream

Figs. 1A, 2D -E, 3A -4A and 5A -B, Table 1

Holotype : MUFS 22854 , male, 167 mm SL, estuary basin of Tung-kang River (purchased in Tung-kang Fish Market), southwestern Taiwan , Y. Iwatsuki , hook-and-line (according to sellers in market) , 22 May, 2005 .

Paratypes : (5 specimens) MUFS 11870 , sex not determined, 110 mm SL, Tung-kang, southwestern Taiwan , M. Akazaki , 25 February 1973 ; MUFS 22165 , sex not determined, 184 mm SL, Tung-kang, southwestern Taiwan , Y. Iwatsuki , 27 December 2002 ; MUFS 22166 , female, 216 mm, same data as MUFS 22165 ; MUFS 22855 , female, 175 mm SL, data same as holotype ; MUFS 22857 , sex not determined, 106 mm SL, mouth of Tungkang River, southwestern Taiwan , Y. Iwatsuki , shrimp set nets , 22 May, 2005 .

Diagnosis

Dorsal fin with 11 or 12 spines and 10 to 12 soft rays; anal fin with 3 spines and 8 or 9 soft rays; 3 ½ scale rows between the fifth dorsal-fin spine base and lateral line; 3 or 4 cheek scale rows; body rounded; ventral infraorbital series above posterior part of upper jaw changing from almost straight to weakly concave with growth (Figs. 2B, 3A); second anal-fin spine robust and dull pointed (Fig. 2C); upper and lower jaws with thin lips, especially anteriorly; broadly rounded rostral-most head squamation with around 10 somewhat smaller scales anteriorly (Fig. 4A); prominent ridge developing just before eye with growth, dorsal head profile becoming slightly convex from snout to just above eye with growth (Figs. 1A, 2B and 3A); upper and lower molar teeth strongly developed and flattened on both sides, gradually more molariform posteriorly (Fig. 5A -B); upper molars in 3 or 4 rows anteriorly and 4 or 5 posteriorly, rows generally irregular, outer third row markedly larger; lower molars in 3 or 4 rows anteriorly and 2 or 3 rows posteriorly, rows generally irregular, the innermost row largest posteriorly (outer second row gently curved outward)(Fig. 5C -D); head and body mostly black, sharply demarcated from whitish belly and chin (Figs. 1A and 3A); a dark spot at top of pectoral-fin base (Figs. 1A and 3A).

FIGURE 1. A Acanthopagrus taiwanensisn. sp. , 22854, holotype, 167 mm SL, Tung-kang, southwestern Taiwan and B A. berda ( Forrskal , 1775) , MUFS 22938, 183 mm SL, Tung-kang, Taiwan.

FIGURE 2. A, Acanthopagrus berda ( Forrskal , 1775) , ZMUC-P 50555 (left side dried skin), holotype, presumably ca. 213 mm SL, Luhaiya, Yemen, Red Sea, B-C, A. taiwanensis , MUFS 22166, paratype, 212 mm SL, Tung-kang, southwestern Taiwan and D-E, ventral edge of first two infraorbitals above posterior part of upper jaw and anal-fin rays of A. berda , ZRC 38094, 249 mm SL, Kisap River, Langkawi Island, Malaysia. Holotype of Acanthopagrus berda ( Forsskal , 1775) .

Description

Counts and measurements of the holotype and 5 paratypes are given in Table 1. In the following description, data for the holotype are presented first, followed by the 5 paratype specimens in parentheses where different. Characters stated in the diagnosis are not repeated.

FIGURE 3. Head of: A, Acanthopagrus taiwanensis , MUFS 22166, paratype, 212 mm SL, Tungkang, southwestern Taiwan and B, A. berda ( Forrskal , 1775) , RMNH 15683, 241 mm SL, Red Sea.

TABLE 1. Counts and morphometric data for the holotype of Acanthopagrus taiwanensisn. sp. and A. berda ( Forsskal , 1775) . Proprtional measurements expressed as percentage of standard length except where noted.

Acanthopagrus taiwanensisn. sp. Acanthopagrus berda
Holotype Paratypes Holotype Non-type specimens
MUFS 22854 MUFS 11870, 22165, 22854, 22855, 22857 n = 5 ZMUC P50555 n = 1 n = 39
Counts:
Dorsal fin rays XI, 11 XI, 11 (XII, 10 and XI, 12 at each) XI, - usually XI, 11 (XII, 10 or XI, 12)
Anal fin rays III, 9 III, 8-9 III, 9 III, 8-9 (usually 9)
Pectoral-fin rays 15 15 15 usually 15 (rarely 14)
Pored lateral-line scales 43 43 or 44 - 42-44
Scales above/below lateral line 4 / 11 3 ½-4 / 11 - 3 ½-4 ½ / 11-12
Scales from 5th dorsal spine base to lateral line 3 ½ 3 ½ 3 ½ 3 ½
Gill rakers 4+9 = 13 4-5+9-10 = 13-15 - 5-7 (usually 5 or 6) + 8-12 (usually 9 or 10) = 13-17 (usually 14 or 15)
Standard length (mm) 167 110-212 ca. 213* 33-288
Proportions:
Body depth 46 45-49 - 45-53 (48)
Head length 33 32-35 32 31-41 (35)
Body width at pectoral fin base 19 17-21 - 13-23 (18)
Snout length 11 9-12 13 11-15 (12)
Orbit diameter 9 9-12 10 8-16 (12)
Dermal eye opening 8 8-11 9 6-14 (10)
Bony interorbital width 9 9-10 - 7-11 (10)
Upper jaw length 13 12-14 13 13-17 (15)
Caudal peduncle depth 13 13-14 - 10-15 (13)
Caudal peduncle length 18 18-20 - 16-23 (18)
Predorsal length 42 41-43 - 42-52 (46)
Preanal length 65 64-73 - 67-74 (71)

to be continued.

TABLE 1 (continued).

Acanthopagrus taiwanensisn. sp. Acanthopagrus berda
Holotype Paratypes Holotype Non-type specimens
MUFS 22854 MUFS 11870, 22165, 22854, 22855, 22857 n = 5 ZMUC P50555 n = 1 n = 39
Prepelvic length 38 35-40 - 35-45 (40)
Dorsal fin base 58 56-60 - 52-64 (58)
Anal fin base 19 18-20 - 16-22 (19)
Caudal fin length 26 28-30 - 12-39 (30)
Pelvic fin spine 17 15-18 18 16-20 (17)
First pelvic fin ray 26 in right 26-29 20 17-31 (26)
Longest pectoral fin ray 37 34-40 41 25-43 (39)
First dorsal fin spine 7 7 - 5-10 (8)
Second dorsal fin spine 12 11-12 - 9-18 (14)
Third dorsal fin spine 15 15-16 - 13-21 (18)
Fourth dorsal fin spine 18 16-19 - 14-22 (19)
Fifth dorsal fin spine 17 16-19 - 14-21 (18)
Sixth dorsal fin spine 16 16-19 - 15-20 (17)
Last dorsal fin spine 12 11-14 - 11-16 (13)
Longest dorsal fin ray 15 14-17 - 14-19 (16)
First anal fin spine 7 6-9 - 5-10 (8)
Second anal fin spine 21 18-23 19 15-26 (22)
Third anal fin spine 15 15-17 15 11-18 (16)
First anal fin ray 19 14-18 - 15-20 (17)
Suborbital depth 5 4 4 3-5 (4)
2nd anal-fin spine / 3rd anal-fin spine 1.39 1.32-1.40 1.27 1.23-1.50 (1.36)

*Standard length estimated from head length using the following regression parameters based on non-type measurements: y = 0.314x, y = head length, x = standard length, R2 = 0.9863.

Body compressed. Mouth somewhat oblique. Maxillary reaching to below middle of pupil and larger than eye diameter. Upper jaw protruding slightly in front of lower jaw. Teeth in jaws in 3 to 5 crowded rows, about 6 (6 or 7) curved canines anteriorly in the upper jaw and 6 in the lower jaw. Suborbital depth greater than dermal eye opening. Anterodorsal profile from above eye gently curved. Profile of occipital ridge distinct above eye. Dorsal-fin spines strong, length of first slightly more than half length of second; second slightly shorter than third; fourth or fifth spine longest. Longest soft dorsal-fin ray shorter than longest dorsal-fin spine. First anal-fin spine short, much less than orbit diameter; second spine robust, its length clearly less than length of head without snout and slightly longer than snout; third anal-fin spine shorter than second spine. First anal-fin ray somewhat shorter than second and third anal-fin spines. Pectoral-fin tip not reaching to vertical through first anal-fin spine base, its length clearly greater than head length. Pelvic fin with first ray somewhat produced, its length shorter than head; pelvic-fin spine longer than snout.

Color (from fresh specimens)

Head and body black (Fig. 1A). Both chin and belly markedly whitish in large specimens, especially over about 180 mm SL. Dorsal, caudal, anal, and pectoral fins black; ventral fins whitish. Color does not change much with preservation.

Distribution

Acanthopagrus taiwanensis is currently known only from Tung-kang, southwestern Taiwan. According to local fishermen and buyers, the species is common around southwestern Taiwan. As the first author did not observe the species in extensive field sampling and examination of museum specimens from Korea, Japan, China (including around Hong Kong and Hainan Island), Vietnam, and elsewhere around Southeast Asia, it may be endemic to Taiwan.

Etymology

The species’ name, “taiwanensis” reflects the type locality, Taiwan.

Discussion

Acanthopagrus taiwanensis and A. berda : Acanthopagrus taiwanensis and A. berda appear to be closely related and are perhaps sister species based on shared specializations. A cladistic analysis of species within this genus is premature as confusion remains about the status of some species and the relation of this genus to Sparidentex ZBK (Orrell & Carpenter, 2004). The combination of body shape, fin coloration and typical number of scale rows above the lateral line is unique for these species within Acanthopagrus ZBK , supporting a close relationship. In addition, the shape of the ventral edge of the first 2 infraorbitals is concave in larger individuals of both species, while it is straight in all other described species of Acanthopagrus ZBK . The concavity is much more pronounced in A. berda than A. taiwanensis and represents a clear difference between the 2 species.

Synonyms of Acanthopagrus berda : Acanthopagrus berda ( Forsskal , 1775) was described on the basis of a dried skin of the holotype (see Table 1; Fig. 2A) from Luhaiya, Yemen, Red Sea. Despite the condition of the holotype, the 4 most important diagnostic characters of this species are evident: a strong concavity of ventral edge of first 2 infraorbitals above posterior part of upper jaw (Figs. 1B, 2A and 3B); 3 ½ scale rows between fifth spinous dorsal-fin spine base and lateral line; anal, ventral, and caudal fins uniformly blackish; and second anal-fin spine longer than third spine. We have examined numerous specimens from throughout the Indo-Pacific, including the Red Sea, that correspond to these key characters. The concavity of the ventral edge of the first 2 infraorbitals is observed in specimens larger than around 130-150 mm SL. The holotype of Sparus hasta Bloch and Schneider ZBK (1801) has the same diagnostic characters as A. berda . Bauchot and Skelton (1986) determined this species to be a junior synonym of A. berda and we concur.

FIGURE 4. Anteriormost head squamation type of A, Acanthopagrus taiwanensisn. sp. , MUFS 22166, paratype, 212 mm SL, Tung-kang, southwestern Taiwan; and B, A. berda ( Forrskal , 1775) , ZRC 38094, 249 mm SL, Kisap River, Langkawi Island, Malaysia.

FIGURE 5. Molar teeth of upper and lower jaws of two sparid species: A -B, Acanthopagrus taiwanensisn. sp. , MUFS 22166, paratype, 212 mm SL, Tung-kang, southwestern Taiwan and C -D, A. berda ( Forrskal , 1775) , SAIAB, 203 mm SL, South Africa.

Sparus calamara Cuvier, 1829 ZBK (based on a drawing of Russell, 1803: pl. 92) is clearly a junior synonym of A. berda , with the following diagnostic characters evident on the drawing: a relatively deep body (52 % of SL, see Table 1); 3 ½ scale rows between the fifth spinous dorsal-fin spine base and lateral line; ventral edge of the first 2 infraorbitals above the posterior part of the upper jaw weakly concave; and black ventral, anal, and caudal fins (Table 1, Figs. 1i -5). Chrysophrys calamara Valenciennes in Cuvier & Valenciennes, 1830 ZBK (preoccupied by Cuvier, 1829), based on 3 syntypes has long been identified as a junior synonym of A. berda by subsequent researchers (Bauchot & Daget, 1972; Bauchot & Skelton, 1986). Day (1875) also described “ Chrysophrys berda var. calamara ZBK ” on the basis of a ZSI F1785’s specimen. However, since the name “ calamara ZBK ”, is preoccupied by Cuvier, 1829, Day’s “ calamara ZBK ” has no taxonomic significance in the context of A. berda .

Castelnau (1861) described Pagrus caffer ZBK (type probably lost, P. Pruvost, pers. comm.) from Durban (Port Natal), South Africa and Smith & Smith (1986) later considered it to be a synonym of A. berda ; we tentatively concur. We examined the holotype of Gilchrist & Thompson’s (1908) Chrysophrys robinsoni ZBK and its characters are consistent with A. berda , including the broadly rounded rostral-most head squamation with small scales anteriorly ( as in Fig. 4B).

Comments on other nominal species assigned to Acanthopagrus ZBK : No type specimen is known for Coius datnia ZBK , described by Hamilton (1822) from the Ganges River mouth, India, but a fine plate (fig. 29 of pl. 9) accompanied the description. This species has long been considered a junior synonym of A. latus (Houttuyn, 1782) because of its yellow pelvic and anal fins (Kottelat, 1986, 2000). However, the absence of molar teeth given in the original description and plate strongly support its placement in the genus Sparidentex ZBK (Bauchot & Smith, 1983) and clearly distinguish it from A. berda and A. taiwanensis . Hamilton’s species needs further study.

Gilchrist & Thompson (1908) described Chrysophrys estuarius ZBK from South Africa. The three syntypes have a relatively slender body and a straight ventral edge of the first 2 infraorbitals above the posterior upper jaw, characters that distinguish it from A. berda and A. taiwanensis .

Chrysophrys schlegelii Bleeker, 1854 ZBK and Mylio butcheri Munro, 1949 ZBK are valid species in the genus Acanthopagrus ZBK from the East Asian Shelf and southern Australia, respectively (Akazaki, 1984; Allen et al., 2002; Cadwallader and Backhouse, 1983; Gomon et al., 1994). They are clearly distinct from both A. berda and A. taiwanensis with slender bodies and 4 ½-5 ½ scale rows between the fifth dorsal-fin spine base and lateral line (vs. 3 ½ for A. berda and A. taiwanensis ). Akazaki (1962) considered Acanthopagrus swinhonis czerskii Berg, 1914 as a junior synonym of A. schlegelii . We did not see the type specimens but followed his idea based on the detailed figure included in the description.

Chrysophrys australis Guenther , 1859 ZBK , C. swinhonis Guenther , 1874 ZBK , C. rubroptera Tirant, 1883 ZBK , Petrus belayewi Hora & Misra, 1943 ZBK , Acanthopagrus sivicolus Akazaki, 1962 ZBK , and Chrysophrys novaecaledoniae Castelnau, 1873 ZBK show 4 ½ scale rows between the fifth dorsal-fin spine base and lateral line (rarely 3 ½ in A. australis and yellowish pelvic- and anal-fin rays, as described in Carpenter, 2001, and 2 of 4 syntypes of C. swinhonis ZBK with 6 ½, as discussed below) on the basis of their type specimens. But C. rubroptera ZBK and A. sivicolus ZBK were confirmed by a fine photograph (Kottelat, 1986) and nontype specimens examined, respectively. In addition, these species have a straight ventral edge of the first 2 infraorbitals above the posterior part of the upper jaw, in contrast to strongly or weakly concave in A. berda and A. taiwanensis .

The taxonomic status of C. swinhonis ZBK has not been examined in detail since the original description by Günther (1859). In 4 syntypes (87-279 mm SL), the pored lateralline scales range from 51 to 56 (vs. 42 to 44 in A. berda and 43 or 44 in A. taiwanensis ), and scale rows between the fifth dorsal-fin spine base and lateral line are 4 ½ or 6 ½. Although a detailed review of C. swinhonis ZBK is still required, it is clearly distinct from both A. berda and A. taiwanensis .

The holotype of Roughleyia palmaris Whitley, 1935 ZBK has 4 scale rows between the fifth dorsal-fin spine base and lateral line, and the upper head profile gibbous (not gibbous in A. berda and A. taiwanensis ). Hutchins (2001) and Allen et al. (2002) regard it as a valid species of Acanthopagrus ZBK confined to southwestern Australia.

TABLE 2. Comparison of selected characters of Acanthopagrus taiwanensisn. sp. and A. berda ( Forsskal , 1775) .

Acanthopagrus taiwanensisn. sp. 110-212 mm SL (n = 3) Acanthopagrus berda 33-288 mm SL (n = 39)
dorsal-fin rays XI-XII, 10-12 usually XI, 11 (XII, 10 or XI, 12)
anal-fin rays III, 8-9 usually III, 9 (rarely 10)
gill rakers 4-5+9-11 = 13-15 5-7 (usually 5 or 6) + 8-12 (usually 9 or 10) = 13-17 (usually 14 or 15)
pored lateral-line scales 43 or 44 42-44
cheek scale rows 3 or 4 5 or 6
upper and lower lips thin thick
ventral edge of the first two infraorbitals above posterior part of upper jaw almost straight but weakly concave in specimens of 210 mm SL strongly concave with growth, in specimens over 130-150 mm SL
anteriormost head scallation from top view rounded with ca. 10 somewhat smaller scales anteriorly rounded with over 20 distinct small scales anteriorly
ridge just before or above eye obvious ridge just before eye in specimen over ca. 180 mm SL concave outline from snout to just above eye with growth and noticeably in specimen over ca. 130-150 mm SL
upper head profile gently convex even with growth concave in specimens over 130-150 mm SL with growth
molar teeth flat somewhat pointed
3rd and 2nd anal-fin spine robust and dull pointed sharply pointed
body color Dense black with clear whitish part of ventral head and abdomen dusky black in whole body
black spot of pectoral-fin base present absent
pelvic-fin color whitish dusky

Although no types of Pagrus macrocephalus Basilewsky, 1855 ZBK are known at ZIN was considered to be a junior synonym of A. schlegelii (Bleeker, 1854) by Akazaki (1962) and Sadovy & Cornish (2000). However, Basilewsky’s (1855), figure 3, tab. I (referred to erroneously as tab. III, fig. 1, which is a sciaenid) is a sparid that is clearly a species of Pagrus ZBK , recognizable by its scaly interorbital area, red body, and 7 or 8 scale rows between the fifth dorsal-fin spine base and lateral line (Tables 1-2)(Akazaki, 1962). Pagrus ZBK macrocephalus ZBK needs further examination and may be a synonym of Pagrus major (Temminck & Schlegel, 1844) .

Richardson’s (1846) Chrysophrys xanthopoda ZBK and C. auripes ZBK from Canton, Chinese Seas are based on BMNH stuffed syntypes that have not been located (J. Maclaine, pers. comm.). However, detailed unpublished color plates of both species in the BMNH library have yellowish pelvic, anal, and caudal fins, especially along with lower margins. These nominal species may, therefore, be junior synonyms of A. latus , which has the same fin coloration (see description of Akazaki, 1962, 1984 and Carpenter, 2001).

Chrysophrys longispinnis Valenciennes in Cuvier & Valenciennes, 1830 ZBK , considered by Bauchot & Daget (1972) to be a junior synonym of A. berda , is unlikely to be that species. Two of 3 syntypes of C. longispinnis ZBK from Bengal have an extremely long second anal-fin spine (1.59-1.60 ratio of second anal-fin spine to third anal-fin spine vs. 1.23-1.50, mean 1.36 in A. berda , and 1.32-1.40, mean 1.37 in A. taiwanensis ; see Table 1). The third syntype from Japan has a relatively deep body and fine minute posteroventral serration of the preopercular flange characteristic of Japanese A. latus (Houttuyn, 1782) (Akazaki, 1962). The type series of C. longispinnis ZBK , therefore, includes 2 species, neither of which is A. berda or A. taiwanensis .

Chrysophrys cuvieri ZBK , described (Day, 1875) from Mangalore, India, has been synonymized with A. berda (Whitehead & Talwar, 1976; Randall, 1995; Ferraris et al, 2000), although the type designation is unclear. Whitehead & Talwar (1976) identified the following potential Day specimens of C. cuvieri ZBK : AMS B.8225, 129 mm SL, Madras; BMNH 1975.9.30.21, 109 mm SL, Cochin; RMNH 1060, not seen by us. The original description and type locality of C. cuvieri ZBK was apparently based on ZSI 1782 although the type was not seen by us. Bauchot & Smith (1983) synonymized C. cuvieri ZBK with Sparidentex hasta (Valenciennes in Cuvier & Valenciennes, 1830) using dentition inconsistent with Acanthopagrus ZBK as a key character. Day’s original description of C. cuvieri ZBK supports this contention since species of Sparidentex ZBK lack the large molariform teeth typically found in Acanthopagrus ZBK . Day’s (1875) description states: “Teeth -four to six sharp, pointed and rather conical incisors in front of either jaw, with villiform teeth behind them: a pointed and compressed row along the outer side of either jaw, the last few of which are small and with rounded crowns; internal to these are two rounded small molars in the lower and three in the upper jaw.” One of Day’s specimens of AMS B.8225 is clearly an example of Sparidentex ZBK without the typical molariform teeth found in Acanthopagrus ZBK . Although its status as a synonym of S. hasta needs to be resolved, C. cuvieri ZBK is clearly distinct from A. berda and A. taiwanensis .

Akazaki (1962) synonymized Sparus chrysopterus Kishinouye, 1907 ZBK (type locality: Kyushu, Shikoku, Inland Sea, Pacific coast of Hondo, Japan) with A. latus . Although the type appears to be lost at ZUMT, Kishinouye (1907) noted that the pelvic and anal fins of S. chrysopterus ZBK are yellow, a character typical of A. latus . The description of the molariform teeth of this species is similar to those of A. schlegelii and clearly places it in the genus Acanthopagrus ZBK , although distinct from A. berda and A. taiwanensis .

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