Metapenaeus joyneri ( Miers, 1880 )

Hsu, Yen-Cheng, Chen, Chien-Lin & Chan, Tin-Yam, 2022, On the penaeid shrimps of the genus Metapenaeus Wood-Mason in Wood-Mason & Alcock, 1891 (Crustacea, Decapoda, Penaeidae) of Taiwan, Zootaxa 5169 (4), pp. 331-346 : 337-341

Metapenaeus joyneri ( Miers, 1880)

( Figs. 5 , 8e )

Penaeus joyneri Miers 1880: 458 , pl. 15-figs. 8-10 (type locality: Japan).

Metapenaeus joyneri — Maki & Tsuchiya 1923: 41, pl. 6-fig. 2.— Chang 1965: 7, 3 unnumbered figs.— Lee & Yu 1977: 100, fig. 70.— Miquel 1982: 99, figs. 41-42— Yu & Chan 1986: 135, fig. 15C, 1 unnumbered fig.— Lee et al. 1999: 445.

Metapenaeus joyneri formosus Lee & Yu 1977: 101 , fig. 71 (type locality: Taiwan).

Material examined. Yilan County, Luodong market, 5 Mar 1985, 2 females cl 21.6, 31.1 mm ( NTOU M02335 ) . Miaoli County, 7 Nov 2005, 1 male cl 14.8 mm, 1 female cl 19.2 mm ( NTOU M02336 ) . Changhua County, Station 2, 19 Mar 2018, 1 female cl 24.3 mm ( NTOU M02337 ) . Yunlin County, Mailiao , 29 Oct 2009, 30 males cl 13.5-18.2 mm, 18 females cl 11.5-18.4 mm ( NTOU M02338 ) ; Station 1, 2 Sep 2009, 3 females cl 14.2-16.9 mm ( NTOU M02343 ); Station 2C, 29 Oct 2009, 1 female cl 24.3 mm ( NTOU M02341 ) ; Station 4A, 29 Oct 2009, 1 female cl 17.9 mm ( NTOU M02342 ) ; Station 4B, 22 Jan 2009, 1 female cl 8.2 mm ( NTOU M02340 ) ; Station X6 17 males cl 14.6-18.6 mm, 18 females cl 14.3-20.4 mm ( NTOU M02339 ) . Chiayi County, Budai fishing port, 5 Mar 2021, 14 males cl 19.1-21.3 mm, 6 females cl 21.8-24.0 ( NTOU M02416 ) , 1 male cl 20.7 mm ( NTOU M02448 , neotype of Metapenaeus joyneri formosus ), 2 males cl 19.4, 20.3 mm ( NTOU M02449 ) .— Dongshi fishing port, 8 May 2012, 1 juvenile cl 6.9 mm ( NTOU M02450 ) . Kaohsiung City, Singda fishing port, 24 Jul 1984, 1 male cl 13 mm, 4 females cl 16.1-18.9 mm ( NTOU M02344 ) . Pingtung County, Donggang fishing port, 5 Mar 2021, 10 females cl 22.0- 24.8 mm ( NTOU M02345 ) , 1 female cl 23.1 mm ( NTOU M02451 ) . Lianjiang County, Nangan , 26 Nov 2000, 3 females cl 21.4-22.0 mm ( NTOU M02346 ) . Kinmen County, 1 Feb 2001, 3 females cl 20.6-21.7 mm ( NTOUM02347 ) . No specific data, 1 male cl 18.6 mm, 2 females cl 19.0, 21.3 mm ( NTOU M02452 ) .

Diagnosis. Rostrum armed with 6–8 (excluding epigastric tooth) teeth on proximal part and dorsal margin, distal 1/3 unarmed, slightly sinuous and more or less extending to tip of antennular peduncle. Pereiopod I with small ischial spine. In males, basial spine of pereiopod III very long and barbed, merus of pereiopod V without basal notch and only with minute to distinct basal tubercle. Telson with minute movable lateral spinules. Male petasma with distomedian projections very long and ribbon-like, far exceeding distolateral projections and with distal parts recurved dorsally. Female thelycum with anterior plate styliform and shaprly pointed anteriorly; coxa of pereiopod IV normal, not expanded or elongated; lateral plates semicircular, extended anteriorly and enveloping anterior plate except for elongated tip of anterior plate.

Coloration. Body greyish white to pale green, densely covered with dark dots. Antennal flagella reddish. Uropods with margins reddish, distal parts proximally somewhat yellowish green and distally reddish. Pleopods somewhat yellowish.

Distribution. Restricted to Japan, Korea, China and Taiwan, intertidal to about 76 m deep ( Miquel 1982; Liu & Zhong 1988; Pérez Farfante & Kensley 1997; Kim 2012)

Remarks. Metapenaeus joyneri can be readily distinguished from the other species of the genus in Taiwan by the rostrum extending to the tip of antennular peduncle and with the distal 1/3 unarmed ( Fig. 5a ). Moreover, both the pestama and thelycum have very different shapes in this species ( Fig. 5b, c ), and the basial spine at the pereiopod III in males are very long and barbed ( Fig. 5e ).

Lee & Yu (1977) noted that some specimens of this species from Donggang (= Tongkang) in southern Taiwan had the carapace relatively more glabrous and robust (i.e., the integument was harder) than the typical form, and recognized it as new subspecies, M. joyneri formosus . One holotype and 12 paratypes were identified but the morphological differences were not illustrated by Lee & Yu (1977). The material reported in Lee & Yu (1977) was deposited either in the Taiwan Fisheries Research Institute or NTOU, the resident institutions of Lee and Yu. An extensive search in the collections of the Taiwan Fisheries Research Institute and NTOU failed to find any specimen labeled as material of this subspecies. In the NTOU are numerous specimens of M. joyneri from Taiwan, including Donggang but almost all are of the typical carapace form, possessing many pubescent sunken areas. There are three males (NTOU M02448 , NTOU M02449 ) and a juvenile (NTOU M02450 ) from Chiayi County (southwestern Taiwan just north of Donggang) that have the carapace relatively more glabrous and with pubescence mainly restricted to the grooves and carinae; characters that fit the description of M. joyneri formosus . They are, however, not from the type locality and are not types.

There is one lot from the old collections in NTOU (NTOU M02452 ) without any location or collection label with three specimens (1 male and 2 females, each attached with a label “3”) that all have the carapace rather glabrous and very similar to the condition of the four naked specimens from Chiayi (NTOU M02448 - M02450 ). While we are confident that NTOU M02452 was collected from Taiwan, there is no precise data even that they may be the types - we just cannot be sure. No size information was given for the types of M. joyneri formosus in Lee & Yu (1977) so we cannot match the present specimens with the type series. The petasma and thelycum illustrated for M. joyneri formosus by Lee & Yu (1977: fig. 71A-C, G) have maximum lengths of 7.5 and 4.8 mm, respectively, according to the scales given for the figures. In the unlabeled lot NTOU M02452 , the petasma of the male is 9.8 mm long and the thelycum of the two females are 2.8 and 3.8 mm long; and as such, the data sets do not agree. Moreover, the telsons of the male and one female have the tips broken while that of the other female does not possess distinct spinules, unlike the telson illustrated by Lee and Yu (1977: fig. 71J). Although we are sure that the specimens of NTOU M02452 are not those used for the illustrations of M. joyneri formosus in Lee & Yu (1977), we cannot ascertain if they are the types. We do know, however, that some Taiwanese penaeid specimens identified by Lee and Yu before 1977 were not included in their 1977 report (e.g., M. ensis: NTOU M 02440 collected on 1 Feb 1974). In addition, both Lee and Yu were always very careful with the labelling of type material when the third author TYC worked with them. The registration numbers indicated in Lee & Yu (1977) for the material of M. joyneri formosus are M 701, M 704 (paratypes), M 705 (holotype) and M 706 (paratype). The label “3” attached to the specimens of the NTOU M02452 lot does not match the registration number of Lee & Yu’s (1977) M. joyneri formosus material. As such, it is unlikely that unlabeled NTOU M02452 are the type specimens of M. joyneri formosus .

An attempt to sequence the barcoding gene COI of the three specimens of NTOU M02542 had failed. The COI (615 bp) of the most glabrous specimen from Chiayi (NTOU M02448 , GenBank ON329768 ), however, is almost identical (sequence similarity 99.7%) with a densely pubescent specimen (NTOU M02451 , GenBank ON329774 ). As none of the types of M. joyneri formosus is found or can be determined, they are now considered as lost. In order to fix the identity of M. joyneri formosus , the sequenced male with nearly glabrous carapace fitting the original description of the subspecies given by Lee & Yu (1977) from Budai, Chiayi (NTOU M02448 ), a locality in southern Taiwan close to Donggang (type locality of M. joyneri formosus ) is now selected as the neotype of M. joyneri formosus . Through this action, M. joyneri formosus , is now synonymized with the nominotypical form.

It may also need to point out that parts of the specimens in the two lots of M. joyneri materials reported in Lee & Yu (1977) are found in NTOU (Nanfang-ao, 5 Apr 1976, 5 specimens, NTOU M02453 ; Keelung fishing port, 9 Mar 1976, 10 specimens, NTOU M02454 ). However, these two lots with labels clearly mentioned that the specimens were caught by fishing boats off the Zhoushan Island at the river mouth of Changjiang River (or Yangtze River) and far from the northern Taiwan (also see Lee & Yu 1977: 100). Therefore, these two lots with specimens not originated from Taiwan are excluded in this work.

Figures

FIGURE 5. Metapenaeus joyneri (Miers, 1880), a, c, female cl 20.6 mm (NTOU M02339); b, d, e, male cl 17.2 mm (NTOU M02339). a, cephalothorax, lateral. b, petasma, ventral. c, thelycum. d, merus of pereiopod V, lateral. e, basial spine of pereiopod III, lateral. Scales: a = 5 mm; b, c, e = 3 mm; d = 1 mm.

FIGURE 8. a, Metapenaeus affinis (H. Milne Edwards, 1838), male cl 22.2 mm (NTOU M02403). b, M. elegans De Man, 1907, male cl 19.1 mm (NTOU M02319). c, M. ensis (De Haan, 1844), female cl 32.7 mm (NTOU M02327). d, M. intermedius (Kishinouye, 1900), female, specimen lost, Dasi fishing port, Yilan county, 26 May 1988. e, M. joyneri (Miers, 1880), female cl 18.4 mm (NTOU M02338). f, M. moyebi (Kishinouye, 1896), male cl 12.3 mm (NTOU M02350).