Haliotrematoides brachyflagellocirrus ( Wang, Liu & Zhou, 2003 ) Kritsky, Delane C., Tingbao, Yang & Yuan, Sun, 2009

Kritsky, Delane C., Tingbao, Yang & Yuan, Sun, 2009, Dactylogyrids (Monogenoidea, Polyonchoinea) parasitizing the gills of snappers (Perciformes, Lutjanidae): Proposal of Haliotrematoides n. gen. and descriptions of new and previously described species from marine fishes of the Red Sea, the eastern and Indo-west Pacific Ocean, Gulf of Mexico and Caribbean Sea, Zootaxa 1970 (1970), pp. 1-51 : 16-17

Haliotrematoides brachyflagellocirrus ( Wang, Liu & Zhou, 2003) n. comb.

( Figs. 24–29)

Syns Haliotrema brachyflagellocirrus Wang, Liu & Zhou, 2003 ; Haliotrema shenzhenensis of Li et al. (2005b), part (nec H. shenzhenensis Wang et al. 2003 ).

Source of current specimens: Lutjanus argentimaculatus (Lutjanidae) : Gulf of Tonkin (South China Sea ) near Lingao , Hainan Province, China (20 o 0' N, 109 o 5' E), 20, 23 September 2003 ; Dapeng Bay near Nanao ( South China Sea ), Guangdong Province, China (23 o 25' N, 117 o 02' E), 24 July 2007 ; South China Sea near Zhanjiang , Guangdong Province, China, 16 July 2004 .

Type host and locality: Type host unknown: Shenzhen, Guangdong Province, China (22 o 27' to 22 o 52'N, 113 o 46' to 114 o 37'E). Type host is likely the mangrove red snapper, Lutjanus argenimaculatus (Forssk å l) ( Lutjanidae ) (see Remarks).

Site of infection: Gills.

Specimens studied: 19 voucher specimens, USNPC 101328, 101329, 101330, BMNH 2008.11.19.18-20, ZSU 20040716–1, 2.

Previous records: Lethrinus nebulosus (Forssk å l): Shenzhen (22 o 27' to 22 o 52'N, 113 o 46' to 114 o 37'E), Guangdong Province, China ( Wang et al. 2003). Sciaenops ocellatus (Linnaeus) : Shenzhen (22 o 27' to 22 o 52'N, 113 o 46' to 114 o 37'E), Guangdong Province, China ( Wang et al. 2003). Identification of L. nebulosus as host for H. brachyflagellocirrus is apparently erroneous (see Remarks).

Redescription: Greatest width of body usually at level of testis. Cephalic lobes well to moderately developed. Posterior eyespots with lenses. Pharynx subspherical to ovate. Testis ovate; germarium subrectangular. Seminal vesicle inconspicuous or absent; MCO comprising proximal funnel-shaped base, tapered tubular shaft with distal counterclockwise coil having about 1 complete ring; prostatic reservoir posterior to MCO, C shaped. Vaginal pore simple within slight tegumental indentation; vaginal vestibule absent; vaginal canal with thick wall, dilated, coiled distally; seminal receptacle inconspicuous. Ventral anchor with short perpendicular superficial root, knob-like deep root, elongate slightly curved shaft, recurved point; distal shaft and point with delicate superficial grooves. Dorsal anchor with elongate truncate superficial root, inconspicuous to nonexistent deep root, slightly curved shaft, recurved point; distal shaft and point lightly grooved. Ventral bar with two submedial pockets along anterior margin; dorsal bar rod-shaped, broadly U shaped. Hook distribution typical.

Measurements: Body 325 (241–385; n = 7) long; greatest width 60 (50–68; n = 7). Haptor 78 (67–95; n = 7) long, 70 (51–82; n = 6) wide. Pharynx 18 (15–20; n = 7) wide. MCO 43 (36–50; n = 5) long. Ventral anchor 49 (46–52; n = 8) long; dorsal anchor 64 (60–71; n = 10) long. Ventral bar 34 (31–36; n = 6) long; dorsal bar 36 (33–38; n = 6) long. Hook 13 (11–14; n = 23) long. Germarium 35 (28–45; n = 5) long, 21 (17–24; n = 5) wide; testis 45 (39–52; n = 4) long, 27 (23–31; n = 4) wide.

Remarks: Haliotrema brachyflagellocirrus Wang, Liu & Zhou, 2003 was described from the gills of fishes identified by its authors as Lethrinus nebulosus (Forsskål) (Lethrinidae) and Sciaenops ocellatus (Linnaeus) (Sciaenidae) from Shenzhen, Guangdong Province, China ( Wang et al. 2003). The host identification of the former species is apparently erroneous. Species of Haliotrematoides (to which Haliotrema brachyflagellocirrus clearly belongs) have never been reported from lethrinid hosts, even though fishes of the Lethrinidae have been frequently examined for monogenoidean parasites ( Yamaguti 1937, 1968; Young 1968; Rascalou & Justine 2007, among others). To the inexperienced, the mangrove red snapper, Lutjanus argentimaculatus , and the spangled emperor, Lethrinus nebulosus , are superficially similar, especially if the red background is absent in specimens of the former fish (see photographs of each species available in Froese & Pauly, 2008), and the two fishes could be confused with each other by the nonspecialist. That Wang et al. (2003) had the mangrove red snapper instead of L. nebulosus is supported by their description of Haliotrema tachypliformis Wang, Liu & Zhou, 2003 from the same hosts as those they report for H. brachyflagellocirrus . Based on comparative morphology, H. tachypliformis is clearly a synonym of Haliotrematoides noncalcaris , a parasite previously known only from Lutjanus argentimaculatus (see Remarks for H. noncalcaris ). As a result, we consider L. argentimaculatus to be the natural host for H. brachyflagellocirrus because 1) Lethrinus nebulosus (an apparent misidentification of Lutjanus argentimaculatus ) was mentioned first within the description of H. brachyflagellocirrus , 2) specimens of the dactylogyrid species obtained for the present study were from L. argentimaculatus , and 3) the parasite occurring on S. ocellatus is clearly an instance of secondary parasitism resulting after introduction of the fish to the coastal areas of China.

The red drum, S. ocellatus , occurs naturally only in the western Atlantic, from Massachusetts in the U.S.A. to the Yucatan Peninsula in Mexico ( Froese & Pauly 2008); it was first introduced to mainland China during the 1990's from North America and has since been successfully cultivated in both fresh and marine waters in the region ( Mao et al. 1997). Dactylogyrids have never been recorded from this fish in North America, and the report of Wang et al. (2003) of species of Haliotrema on red drum in China apparently represent parasitism acquired from a native fish, probably Lutjanus argentimaculatus , subsequent to introduction of the fish into the western Pacific.

Although access to the type specimens of Haliotrema brachyflagellocirrus was not allowed, this species is transferred to Haliotrematoides as H. brachyflagellocirrus ( Wang, Liu & Zhou, 2003) n. comb. based on comparison of the figures provided by Wang et al. (2003) with present specimens from L. argentimaculatus . Wang et al. (2003) did not compare H. brachyflagellocirrus with the similar H. noncalcaris , nor with its synonym, Haliotrema tachypliformis . H. brachyflagellocirrus and H. noncalcaris share morphologically identical MCO’s. However, they are easily differentiated by H. brachyflagellocirrus having ventral anchors with comparatively short poorly developed roots and with the superficial root nearly perpendicular to the anchor base (ventral anchor roots well defined and with the superficial root arising from the anchor base at about a 45 o angle in H. noncalcaris ), a smaller dorsal anchor base (anchor base about one third the total anchor length in H. brachyflagellocirrus ; about one half that in H. noncalcaris ), and a dorsal bar lacking a posteromedial expansion (dorsal bar with an expansion in H. noncalcaris ) (compare Figs. 24–35 and Bychowsky & Nagibina 1971). Finally, the copulatory and haptoral sclerites of H. brachyflagellocirrus are noticeably smaller than those of H. noncalcaris .

Li et al. (2005b) recorded Haliotrema shenzhenensis from two fish hosts off the China coast: Sparus macrocephalus (Basilewsky) (Sparidae) and L. argentimaculatus . Their drawings of H. shenzhenensis suggest that at least two species of dactylogyrids were included, with those ( Figs. 1 e–h) from L. argentimaculatus representing H. brachyflagellocirrus and those ( Figs. 1 a–d) from S. macrocephalus representing another, perhaps undescribed species of Haliotrematoides .