BOPYRIDAE Rafinesque-Schmaltz, 1815

An, Jianmei, Boyko, Christopher B. & Li, Xinzheng, 2013, A review of the genus Parapenaeonella (Isopoda: Bopyridae: Orbioninae), with description of a new species from Chinese waters and synonymy of Parapenaeonella lamellata Bourdon, 1979, Journal of Natural History 47 (41 - 42), pp. 2633-2648 : 2634-2644

Family BOPYRIDAE Rafinesque-Schmaltz, 1815

Subfamily Orbioninae R. Codreanu, 1967 Genus Parapenaeonella Shiino, 1949 Parapenaeonella distincta Shiino, 1949

( Figures 1–7)

Type species: Parapenaeonella distincta Shiino, 1949 , by monotypy

Parapenaeonella distincta Shiino, 1949: 59–60 , fig. 1 [type locality: Choshi Fish Market, Chiba Prefecture, Japan, infesting Trachysalambria curvirostris (Stimpson, 1860) ]. Shiino, 1958: 50–51, fig. 12 [Aritaki, Tsu and Momotori, Mie Prefecture, Japan, depth not stated; infesting T. curvirostris ). Bourdon, 1981: 253–255, figs. 14–15 [13 ◦ 59.8 ′ N, 120 ◦ 23.7 ′ E to 14 ◦ 00.9 ′ N, 120 ◦ 21.5 ′ E, Philippines, 217–230 m depth, infesting unidentified Penaeidae sp.]. Owens, 1986: 15 (list). Owens, 1987: 121 (list). An, 2006: 156–157, fig. 80 [Guangdong Province, China; infesting Metapenaeus affinis (H. Milne-Edwards, 1837) ].

Parapenoeonella (sic) distincta Bourdon, 1968: 406–407 (list).

Parapenaeonella lamellata Bourdon, 1979: 425–428 , figs. 1–3 [17 ◦ 54 ′ N, 72 ◦ 27 ′ E to 17 ◦ 57 ′ N, 72 ◦ 23 ′ E, Arabian Sea off the Indian coast, 46–55 m depth, infesting Metapenaeus monoceros (Fabricius, 1798) ; 15 ◦ 08 ′ N, 94 ◦ 54 ′ E, Andaman Sea midway between Andaman Islands and Burmese coast, 35 m depth, infesting Metapenaeus ensis (De Haan, 1844) ]. Bourdon, 1981: 255 (comparison with P. distincta ). Markham, 1982: 365 (mention). Miquel, 1982: 94 (mention). Owens and Glazebrook, 1985: 107 [Gulf of Carpentaria, Northern Territory / Queensland, Australia, infesting M. ensis ]. Owens, 1986: 15, 84, 98 [Gulf of Carpentaria, Northern Territory / Queensland, Australia, infesting M. ensis ]. Owens, 1987: 118 (list). Owens, 1990: 35, 37 [Queensland, Australia, infesting M. ensis and Metapenaeus endeavouri (Schmitt, 1926) ]. Owens, 1993: 384 (mention). Humphrey, 1995: table 48 (list). Kensley, 2001: 225 (list). Kazmi et al. 2002: 55, fig. 8 (after Bourdon, 1979). Poore, 2002: 126 (list). An, 2006: 160–161, plate 13 [Qingdao fish market, Shandong Province, China; infesting Trachypenaeus curvirostris ]. Markham, 2010 (list) (syn. nov.).

Parapenaeolla (sic) lamellata Kazmi et al. 2002: 54 (list).

Parapenaeonella gigans sp. nov. An, 2006: 157–159, fig. 81 [The Yellow Sea, China; infesting Trachypenaeus curvirostris ] (unavailable name).

Parapenaeonella longicauda sp. nov. An, 2006: 159, fig. 82, plate 12 [[Qingdao fish market, Shandong Province, China; infesting Trachypenaeus curvirostris ] (unavailable name).

Material examined

Infesting Metapenaeus affinis (H. Milne-Edwards, 1837) , det. of host, Ruiyu Liu. CIEPE621601 , ♀, ♂, Guangdong Province, 22 ◦ 26 ′ N, 113 ◦ 43 ′ E, 2 March 1956, coll. Baoling Wu.

Infesting Trachysalambria curvirostris (Stimpson, 1860) . CIEPE010401 , ♀ , CIEPE010402 , ♂ , Yellow Sea, Stn. D8, 36 ◦ 02 ′ N, 120 ◦ 22 ′ E, 83 m, 2 April 2001. CIEPE041201 , 10♀♀, 10♂♂ , CIEPE041202 , 2♀♀, 2♂♂ , CIEPE041203 , 2♀♀, 2♂♂ , CIEPE041205 , 2♀♀, 2♂♂ , CIEPE041206 , 2♀♀, 2♂♂ , CIEPE041204-1 , ♀ , CIEPE041204-2 , ♂ , CIEPE041204-3 , ♀ , CIEPE041204-4 , ♂ , CIEPE041201-1 , ♀, ♂ , bought from Qingdao fish market by Fengshan Xu.

Description of reference female (CIEPE041204-1)

Length 12.23 mm, maximal width 8.98 mm across third pereomere, head length 2.12 mm, head width 2.49 mm. All body regions and segments distinct, nearly symmetrical. No pigmentation ( Figure 1A, B).

Head heart-shaped, frontal lamina broad, laterally expanded, wider than head; eyes lacking ( Figure 1A). Antennae and antennules of six and three articles, respectively ( Figure 1C), without setae. Barbula ( Figure 1D) with two digitate projections on each side, external projections slightly larger; three or four tubercules near internal projections. Maxilliped ( Figure 1E) with curved palp, anterior article much larger than posterior one.

Pereomeres distinct, third one broadest. All pereomeres with conspicuous coxal plates on both sides. Dorsolateral bosses on both sides of first four pereomeres and obscure on right fifth pereomere. Brood pouch completely covered by oostegites. First oostegite ( Figure 1F, G) with digitate internal ridge and round posterolateral point. Pereopods larger posteriorly, basal articles with tubercules on surface, dactyli embedded in propodi ( Figure 1H, I).

Pleon of six pleomeres, first five produced into lateral plates, tuberculate on ventral surface except first lateral plates ( Figure 1J). All pleopods biramous, strongly tuberculate and visible only ventrally ( Figure 1B). First pleopod ( Figure 1K) lamellar, much larger than other pleopods, endopodite larger than exdopodite. Second to fifth pleopods ( Figure 1L–O) progressively smaller posteriorly. Uniramous uropods strongly tubercular.

Description of reference male (CIEPE041204-2)

Length 3.63 mm, maximal width (across fifth pleomere) 1.77 mm, head width 0.83 mm, pleonal length 0.84 mm. All pereon segments distinct, but pleon fused in median part ( Figures 2A, B, 3A).

Head an inverted triangle, bearing small eyes near anterior edge ( Figure 2A). Antennae and antennules of six and three articles, respectively; total length of antennae slightly more than twice length of antennules, terminal setae present ( Figure 3B, C).

Fifth pereomere widest; all pereomeres laterally acuminating, posteriorly sharply pointed. Midventral projections lacking ( Figures 2B, 3A). All pereopods subequal in size and shape, each with ridged, grooved protuberance on distoventral surface of propodus into which dactyli insert ( Figure 3D, E).

Pleon of six pleomeres, fused in median region, separated by lateral margin ( Figure 2B). First five pleomeres with lateral plates and long and filiform uniramous pleopods ( Figures 2B, 3A). Sixth pleomeres without lateral plates, but with long uropods similar to pleopods ( Figure 2B).

Remarks

This is fifth record of this species, found only on penaeid hosts. The first two reports were from Japan with all other records from the Indian Ocean and the western Pacific Ocean. Shiino (1949) erected the genus Parapenaeonlla based on the type species P. distincta Shiino, 1949 , and described the species in detail. The key character of the genus is that the male has more or less distinct abdominal segments and posseses filiform pleopods. However, the figure of Shiino (1949: fig. 1C, D) shows the pleon of the male as incomplete, possibly broken. Shiino (1949) reported the abdomen as five-segmented and the first four pleomeres with lateral plates, but in Chinese specimens from the same host ( Trachypenaeus curvirostris ) as the type specimens, the male pleon has six segments, the first five bearing lateral plates ( Figure 2A–D). Shiino (1949) described the male as lacking uropods, but in the present specimens uropods are present ( Figure 2A, C). Shiino (1958) recorded this species again from the type host, but with the male abdominal segments entirely fused into a single triangular piece, the boundaries between consecutive segments being indicated merely by undulation of the lateral sides, indicating the presence of five fused segments, and with five pairs of tuberculate pleopods present. Some Chinese specimens are also found with fused abdomens of the Shiino (1958) type ( Figures 2H, I, G, 3A, 4K, L, 5A, G).

Bourdon (1979) described P. lamellata infesting Metapenaeus monoceros (Fabricius) and distinguished it from P. distincta , but he did not mention the specimens described by Shiino (1958) showing the male pleon variations. This was a critical oversight, as Bourdon’s male was very similar to the male in Shiino (1958). One present specimen (CIEPE621601) ( Figure 6), also from a host in the genus Metapenaeus , shows the male ( Figure 6J, K) with a distinct first pleomere and the first five pleomeres with triangular lateral plates and digitate pleopods. Because both male forms have been found on the type host from Japanese localities, and the males of Bourdon (1979) are nearly identical to those reported by Shiino (1958), we consider P. lamellata a synonym of P. distincta . Bourdon (1981) reported P. distincta infesting an unidentified penaeid from the Philippines with that male being similar to one of our Chinese males ( Figure 6J, K).

Based on the five reports to date of P. distinca and P. lamellata , we suggest that the developmental process of the male of P. distincta can be divided into three stages. In the first stage the male is immature and the pleon is entirely fused and the pleomeres obscure ( Figures 2G, H, I, 4K, L, 5A); this can also be seen in fig. 12 of Shiino (1958) and figs 1b, 2e of Bourdon (1979). The middle stage has the male with distinct first pleomeres and digitate pleopods ( Figures 2E, F, 6J, K, 7A, G and figs 14b, 15c of Bourdon, 1981). The last stage of the male is mature, with the pleon only fused in the median and with the first five pleomeres bearing filiform lateral plates and uniramous pleopods ( Figures 2A–D, 3A and fig. 1C, D of Shiino, 1949).

Earlier studies of this Chinese material by one of the authors (JA) resulted in the conclusion that two new species existed in the material, as well as P. distincta . Both P. gigans sp. nov. and P. longicauda sp. nov., were listed by name in her doctoral dissertation. For the reasons elaborated above, we now consider all these materials to represent one species with recognized variability in male pleon morphology. The names P. gigans and P. longicauda were not available from the dissertation (not a published work in the sense of the ICZN) and are introduced here in synonymy and are likewise not made available (ICZN Article 11.6). We include these names here to avoid future confusion regarding their status.