Cymothoa indica

Martin, Melissa B., Bruce, Niel L. & Nowak, Barbara F., 2016, Review of the fish-parasitic genus Cymothoa Fabricius, 1793 (Crustacea: Isopoda: Cymothoidae) from Australia, Zootaxa 4119 (1), pp. 1-72 : 28-29

Cymothoa indica S chioedte & Meinert, 1884

Cymothoa Indica Schioedte & Meinert, 1884: 250 , tab. VIII (Cym. XXVI) figs. 1–4.

Cymothoa indica .— Chilton, 1924: 887.— Hale, 1926: 212, fig. 8 (a–k).— McNeill, 1926: 318.— Nierstrasz, 1931: 133, fig. 1, pl. 10 (figs. 5–8).— Avdeev, 1978b: 282; 1982b: 69.— Trilles, 1975: 981, pl. I (6, 7); 1994: 144; 2008: 23.— Veerapan & Ravichandran, 2000: 1.— Kensley, 2001: 232. — Bruce, Lew Ton & Poore, 2002: 175.— Rajkumar, Santhanam & Perumal, 2004: 113.— Rajkumar, Perumal & Trilles, 2005a: 87, figs. 1, 2.— Rajkumar, Vasagam, Perumal & Trilles, 2005b: 269.— Trilles & Bariche, 2006: 223, figs. 1–3.— Ravi & Rajkumar, 2007: 251, fig. 2.— Jones, Miller, Grutter & Cribb, 2008: 477.— Trilles, Ravichandran & Rameshkumar, 2011: 446.

Uncertain identity

Cymothoa sp. Monod, 1934: 14, pl. 28 (a–b), pl. 30 (d).

Cymothoa indica .— Panikkar & Aiyar, 1937: 429.— Rameshkumar & Ravichandran, 2010: 67, fig. 1.— El-Shahawy & Desouky, 2010: 107, fig. 1 (a, b).— Al-Zubaidy & Mhaisen, 2014: 58, figs. 1, 2.

Type material. The syntypes (1 ovig. ♀, 20 mm; 1 immature ♂, 9 mm) were collected from Bangkok from an unknown host ( Schioedte & Meinert 1884).

Requests were made for the material but it is not held in the collection of the Zoological Museum, Museum für Naturkunde, Berlin (Oliver Coleman, personal communication) nor the Zoological Museum of Copenhagen, Denmark (Jørgen Olesen, personal communication).

Material examined. Northwestern and northeastern Queensland material: 1 ovig. ♀ (22 mm), 1 immature ♂ (11 mm), Stn. 506, Gulf of Carpentaria, 12°36.8’S, 141°18.4’E, December 1990, trawled J. Smith, FRV “Southern Surveyor”, 36.5 m depth, from silvermouth trevally Ulua aurochs (Ogilby, 1915) , coll. CSIRO (MTQ W17481). 1 ovig. ♀ (20 mm), Stn. 470, southeastern Gulf of Carpentaria, 16°77.83’S, 139°52.17’E, 7 m depth, 14 December 1963, from Cynoglossus sp., Cat. # 470, coll. CSIRO Fisheries on trawler “ Rama ” (AM P89834). 2 ovig. ♀ (20, 26 mm), Bowen Harbour, Port Denison, 20°02.0’S, 148°25.0’E, year 1926, coll. E. H. Rainford (AM P8574). 2 mature ♂ (10, 12 mm), Bowen, Port Denison, 20°05.0’S, 148°25.0’E, coll. E. H. Rainford (AM P9587). 1 ♀ (15 mm), Bowen Harbour, Port Denison, 20°02.0’S, 148°25.0’E, year 1925, coll. E. H. Rainford (AM P8484). 2 ovig. ♀ (16, 18 mm), 1 mature ♂ (15 mm), Bowen, from whiting, coll. E. H. Rainford (MTQ W197). 1 ovig. ♀ (20 mm), 1 immature ♂ (10 mm), Bowen Harbour, Port Denison, 20°02.0’S, 148°25.0’E, year 1926, from Sillago sp., coll. E. H. Rainford (AM P8573). 1 mature ♂ (15 mm), off Cooktown, November 1975, from trevally, coll. S. Tanner (MTQ W5745). 1 non-ovig. ♀ (16 mm), 1 mature ♂ (12 mm), Townsville, from inside fish (MTQ W10273).

Central Queensland material: 1 non-ovig. ♀ (19 mm), 1 immature ♂ (10 mm), Yeppoon, 23°08.0’S, 150°41.0’E, 24 June 1991, from bumpnose trevally Carangoides hedlandensis (Whitley, 1934) , coll. G. Monteith (MTQ W17483). 1 immature ♂ (10 mm), Northwest Island, 23°03.0’S, 151°07.0’E, December 1925, coll. G. P. Whitley (AM P8559). 1 ovig. ♀ (30 mm), Northwest Island, 23°03.0’S, 151°07.0’E, 27.4 m depth, December 1929 – January 1930, coll. Mel Ward (AM P89954). 1 immature ♂ (6 mm), Port Curtis, 23°04.0’S, 150°05.0’E (AM P9600).

Southeastern Queensland material: 2 ovig. ♀ (15, 17 mm), 1 immature ♂ (6 mm), Stn. 4, Mary River, 12 October 1981, from tongue of Sillago sp. (MTQ W10429). 1 immature ♂ (8 mm), Mary River, 14 April 1982 (MTQ W11015). 1 ovig. ♀ (23 mm), 1 immature ♂ (10 mm), Moreton Bay, 27°17.0’S, 153°15.0’E, year 2005, from sand sillago Sillago ciliata Cuvier, 1829 , GENBANK # E422801, coll. Mieke Burger (MTQ W28288) (see Jones et al. 2008). 1 ovig. ♀ (20 mm), No. 77, Southport, year 1920, from the gills of long tom, coll. R. Pohlman (MTQ W5761). 2 ovig. ♀ (18, 24 mm), 1 ♂ (10 mm), Hollywell, Southport, 8 April 1953, from gill slits of eel, coll. Hale (MTQ W6005).

Non-Australian material: 1 ♀ (15 mm), Vanuatu, Erromango, Port Narvin, 18°74.1’S, 169°21.1’E, 28 May 1996, coll. M. M Grouther and J. Williams (AM P89837). 1 ♀ (23 mm), examined by Hale without other available data (AM P89832).

Colour. Present material ranges from pale yellow to dark brown. Some of the ovigerous female specimens from Sillago ciliata are darker at the anterior region of the body and are progressively lighter posteriorly.

Size. Ovigerous females: 15–30 mm; males: 6–15 mm (present material).

Remarks. Cymothoa indica has a subtriangular cephalon; pereonite 1 anterolateral margins minute and not reaching the middle of the cephalon; pereopod 7 ischium inferior distal margin with a distinctive lobe; pleotelson posterior margin subtruncate; and uropodal rami of similar length as pleotelson posterior margin (for figure examples see Hale 1926; Trilles 1975; Trilles & Bariche 2006). The present study showed that the eyes vary from being either absent or moderately visible, pleotelson similar or wider than pereonite 7, cephalon deeply embedded in pereonite 1 or dorsally visible, and pereopod 7 basis with moderately or highly raised carina.

Cymothoa indica resembles Cymothoa plebeia Schioedte & Meinert 1884 and C. frontalis in the body size, cephalon and pleotelson morphology. Cymothoa frontalis is identified by the non-linear posterior margins of pereonites; pereonites posterolateral margins convex; and dactyli of pereopods 1 and 2 slender and long, and nearly touching the merus. Cymothoa plebeia is recognised by the lack of the prominent ischium lobe of C. indica and the smooth pereon posterior margins.

We regard the two records of C. indica from the Red Sea ( El-Shahawy & Desouky 2010; Al-Zubaidy & Mhaisen 2014) as doubtful. El-Shahawy & Desouky (2010) provided figures of only pereopod 7, “showing the characteristic lobe on the postero-angle of the ischium”, however, the figures portray a distinct protrusion on the merus and not the ischium, which is not seen in C. indica . Al-Zubaidy & Mhaisen’s (2014) specimens [reported from blue spot mullet Moolgarda seheli (Forsskål, 1775) ] would appear similar to C. eremita in the subtruncate cephalon and pereonite 1 reaching half the length of cephalon.

Trilles et al. (2011) mentioned that Panikkar & Aiyar (1937) collected 51 Cymothoa indica specimens from two localities near the Madras coast (the Adyar backwaters and four miles up the river from Adyar) from several host species (mainly the freshwater orange chromide cichlid Etroplus maculatus (Bloch, 1795) and pearlspot cichlid Etroplus suratensis (Bloch, 1790)) . Without a description or access to the specimens, we exclude this record from synonymy. We also agree with Trilles et al. (2011) that the record of C. indica on tilapia Oreochromis mossambicus (Peters, 1852) by Rameshkumar & Ravichandran (2010) is a misidentification and that record is also removed from synonymy.

Distribution. Known from southeastern Pacific and Indian Ocean: Bangkok ( Schioedte & Meinert 1884); Beirut (see Trilles & Bariche 2006); India ( Chilton 1924; Veerapan & Ravichandran 2000; Rajkumar et al. 2004, 2005a, 2005b; Ravi & Rajkumar 2007; Trilles & Bariche 2006; Trilles et al. 2011); Australia ( Hale 1926; McNeill 1926; Jones et al. 2008); Indonesia ( Nierstrasz 1931; Trilles 2008); Vietnam ( Trilles 1975).

Hosts. Current studies are from host families Carangidae , Cynoglossidae , Sillaginidae and an unknown eel.

Previously reported from host of the family Bagridae : long whiskers catfish, Mystus gulio (Hamilton, 1822) ; Belonidae : spottail needlefish, Strongylura strongylura (van Hasselt, 1823) (see Rajkumar et al. 2004); Clupeidae : Bloch's gizzard shad Nematolosa nasus (Bloch, 1795) ; Gobiidae : maned gobi, Oxyurichthys macrolepis (Bleeker, 1849) (see Ravi & Rajkumar 2007), goby Glossogobius giuris (Hamilton, 1822) (see Chilton 1924); Latidae : larvae of barramundi, Lates calcarifer (Bloch, 1790) (see Rajkumar et al. 2005a); Siganidae : streaked spinefoot Siganus javus (Linnaeus, 1766) (see Rajkumar et al. 2005b); Sparidae : common pandora Pagellus erythrinus ( Linnaeus, 1758) (see Trilles & Bariche 2006); Sphyraenidae : yellowstripe barracuda Sphyraena chrysotaenia Klunzinger, 1884 (see Trilles & Bariche 2006), obtuse barracuda Sphyraena obtusata Cuvier, 1829 (see Veerapan & Ravichandran 2000; Trilles & Bariche 2006); Synodontidae : snakefish Synodus myops (Forster, 1801) (previously Trachinocephalus myops ) (see Veerapan & Ravichandran 2000; Trilles & Bariche 2006).