Cymothoa parupenei Avdeev, 1979

Figures 16–17

Cymothoa parupenei Avdeev, 1979a: 228, pl. 4–5.— Trilles, 1994: 147.— Kensley, 2001: 233. — Bruce, Lew Ton & Poore, 2002: 175.— Trilles & Bariche, 2006: 228. — Rameshkumar, Ravichandran, Sivasubramanian & Trilles, 2013: 42, fig. 1(A).

Material examined. Paratype: 1 mature ♂ (13 mm), from the Indian Ocean off Australia, from blackspot goatfish Parupeneus spilurus (Bleeker, 1854) (TINRO АPK 75027). A loan request was made for the holotype (TINRO AGK 75026) but the specimen could not be located.

Male Length 13.5 mm width 7 mm (paratype).

Body subrectangular, 1.8 times as long as greatest width, dorsal surface smooth, widest at pereonite 5, most narrow at pereonite 1. Cephalon 0.5 times longer than wide, visible from dorsal view, semi-circular. Frontal margin rounded to form blunt rostrum. Eyes partially visible. Pereonite 1 anterolateral margins broad, nearly reaching anterior margin of cephalon; pereonites 1–6 posterior margin smooth, laterally concave; pereonites 5–7 subequal in length. Coxae 2–7 posteroventral margins rounded. Pleonite 1 similar length to pleonites 2–5, visible in dorsal view; pleonites posterior margin moderately irregular; pleonites 3–5 progressively wider. Pleotelson 0.5 times as long as anterior width, anterior margin not trisinuate, lateral margin weakly concaved, posterior margin subtruncate and irregular, without median point.

Antennula comprised of 8 articles; peduncle articles 1 and 2 distinct and articulated; article 2 1.3 times as long as article 1; article 3 0.6 times as long as combined lengths of articles 1 and 2, 0.9 times as long as wide. Antenna comprised of 9 articles, peduncle article 3 2.0 times as long as article 2, 1.0 times as long as wide; article 4 1.1 times as long as wide; article 5 0.8 times as long as article 4, terminal article without setae.

Pereopod 1 basis 1.7 times as long as greatest width, superior proximal margin smooth, without raised carina; ischium 0.6 times as long as basis; merus proximal margin without bulbous protrusion; carpus with straight proximal margin; propodus 1.4 times as long as wide; dactylus narrow, 1.5 times as long as propodus, 2.6 times as long as basal width. Pereopod 2 basis 1.6 times as long as greatest width, superior proximal margin smooth, without raised carina; propodus 1.1 times as long as wide; dactylus 1.4 times as long as propodus. Pereopods 3–5 similar to pereopod 2, gradually increasing in size, without robust or simple setae. Pereopod 6 basis 1.2 times as long as greatest width, superior proximal margin smooth, with sharp and raised carina; ischium 0.6 times as long as basis, propodus 1.3 times as long as wide, dactylus 2.1 times as long as propodus. Pereopod 7 basis 1.3 times as long as greatest width; ischium 0.9 times as long as basis, inferior margin with slight bulbous protrusion; merus proximal margin without bulbous protrusion, merus 0.3 times as long as ischium, 0.5 times as long as wide; carpus 0.3 times as long as ischium, without bulbous protrusion, 0.6 times as long as wide; propodus 0.7 times as long as ischium, 0.6 times as long as wide; dactylus stout, 1.8 times as long as propodus, 2.3 times as long as basal width.

Uropod reaching posterior margin of pleotelson, peduncle 1.1 times as long as greatest width, 0.8 times as long as exopod, lateral margin without setae, marginal setae absent, apices broadly blunt, lateral margin convex, mesial margin convex. Exopod extending past endopod, 3.6 times as long as greatest width, apically rounded, lateral margin straight, terminating without setae, mesial margin weakly straight. Endopod 3.0 times as long as greatest width, apically rounded, lateral margin weakly convex, terminating without setae, mesial margin straight.

Colour. Light brown in ethanol (present study), ivory white in Rameshkumar et al. (2013).

Remarks. Cymothoa parupenei can be identified by the wide anterolateral margins on pereonite 1 extending beyond the anterior margins of cephalon; semi-circular cephalon anterior margin (subtruncate cephalon in holotype); pleonite 1 almost entirely overlapped by pereonite 7; uropods reaching posterior margin of the pleotelson; pereopod 7 basis with smooth and moderately raised carina, ischium inferior distal margin with slight bulbous projection; and pleotelson 2.1 times wider than long (2.6 times wider than long in holotype). Avdeev’s (1979a) illustration of the ovigerous female showed a maxillula with 3 terminal setae; lateral lobe of maxilla partly fused to mesial lobe, with 1 recurved seta on each mesial and lateral lobe; a weakly segmented maxilliped, terminal article 3 with 3 recurved robust setae; pleopod 1 rami of subequal size; endopod mesial margin deeply oblique and distally straight, lateral margins deeply convex, with proximal margins extending beyond peduncle. The male pleopod 2 (illustrated by Avdeev 1979a, fig. 5) has an appendix masculina half the exopod length; exopod lateral margin weakly convex, with medial margin distally rounded and weakly convex.

Cymothoa parupenei resembles Cymothoa oestrum (Linnaeus, 1758) in the semi-circular cephalon, pereonites 1–6 posterior margin smooth and pleonites 3–5 becoming progressively wider. Cymothoa oestrum differs from C. parupenei in having anterolateral margins of pereonite 1 that project forward (compared to the more broad and concave anterolateral margins of C. parupenei) and pereopods 5–7 basis have sharp carinae visible in lateral view (see Thatcher et al. 2003) compared to blunt carina of Avdeev’s (1979a) specimens. Cymothoa parupenei is host specific to Mullidae and has an Indo-Pacific distribution, whereas C. oestrum is known from a variety of fishes and has a western Atlantic distribution (Thatcher et al. 2003).

Rameshkumar et al. (2013) recorded a prevalence of 5.9% (1 in 17 hosts) captured at Nagapattinam, India.

Distribution. Reported from northwestern Australia (Avdeev 1979a; Kensley 2001) and India (Rameshkumar et al. 2013).

Hosts. Known from family Mullidae: Parupeneus spilurus (see Avdeev 1979a) and sulphur goatfish Upeneus sulphureus Cuvier, 1829 (see Rameshkumar et al. 2013).