Hatschekia maculatus, Lee & Lee & Boxshall, 2013

Lee, Soyoung, Lee, Wonchoel & Boxshall, Geoffrey, 2013, Seven new species of Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on fishes of New Caledonia, and a redescription of H. cadenati Nunes-Ruivo, 1954, Zoosystema 35 (3), pp. 377-413 : 380-382

Hatschekia maculatus n. sp.

Hatschekia sp. 10 – Justine et al. 2010a: fig. 1E.

TYPE HOST. — Epinephelus maculatus (Bloch, 1790) ( Perciformes : Serranidae ).

TYPE LOCALITY. — Récif Toombo, New Caledonia (22°32’59’’S, 166°28’59’’E).

ETYMOLOGY. — The specific name of the new species, maculatus, is treated as a noun in apposition and is derived from its host fish.

MATERIAL EXAMINED. — Holotype female (MNHN- IU-2013-4001) dissected on 14 slides. Paratype female ( NHMUK 2012.263) dissected on 5 slides. 89 ♀♀ undissected paratypes (2 ♀♀ used for SEM) from E. maculatus [JNC1907], Récif Toombo, New Caledonia (22°32’59’’S, 166°28’60’’E), coll. J.-L. Justine, 18.VII.2006. 40 ♀♀ undissected in MNHN-IU-2013-4002), 27 ♀♀ undissected in NHMUK 2012.264-273, 20 ♀♀ undissected in MABIK CR00179889-CR00179908.

ADDITIONAL MATERIAL. — 1 ♀ from E. maculatus [JNC1522] ; Récif Aboré , New Caledonia (22°21’20’’S, 166°15’30’’E), coll. J.-L. Justine, 21.IV.2005. ( NHMUK 2012.274 ) ;

21 ♀♀ from E. maculatus [JNC1523]; Récif Aboré , New Caledonia (22°21’20’’S, 166°15’30’’E), coll. J.-L. Justine, 21.IV.2005. (MNHN-IU-2013-4003) ;

5 ♀♀ from E. maculatus [JNC1524]; Récif Aboré , New Caledonia (22°21’20’’S, 166°15’30’’E), coll. J.-L. Justine, 21.IV.2005. ( NHMUK 2012.286 - 290 ) ;

39 ♀♀ from E. maculatus [JNC 1908]: Récif Toombo , New Caledonia (22°32’59’’S, 166°28’60’’E), coll. J.- L. Justine, 18.VII.2006. ( NHMUK 2012.275 - 284 ) ;

DNA-barcode (mtCOI) sequences and traces were submitted to GenBank (accession number: JQ 664005 ).

DESCRIPTION

Female

Total body length 790-892 Μm (n = 12, mean = 836 Μm) excluding caudal rami. Body ( Fig. 1A ) dorsoventrally depressed, with integument separated by gap from internal body tissues. Cephalothorax ( Fig. 1A ) oval, longer than wide (377 × 304 Μm), widest in anterior third and narrowing posteriorly towards strongly convex posterior margin; dorsal surface with distinct chitinous markings in form of “m-shape”, bar in mid-line extending well beyond branched posterior tips of curved lateral bars; bar in mid-line with short oblique lateral branches near base.Trunk ( Fig. 1A ) rectangular, longer than wide (515 × 292 Μm), with irregularly parallel lateral margins narrowing in posterior fifth to posterior margin bearing paired postero-lateral processes; each process comprising wider proximal part and narrow, conical distal part, all with wrinkled cuticle ( Fig. 1A ). Urosome ( Fig. 2E ) tapering posteriorly, shorter than wide (74 × 95 Μm), unsegmented comprising fused genital complex and abdomen ( Fig.2E ). Caudal ramus ( Fig. 2E ) elongate, elliptical, longer than wide (53 × 19 Μm), with five naked distal setae and one plumose lateral seta. Egg sacs shorter than trunk, mean of 4.0 eggs per sac, range from three to seven eggs per sac.

Rostrum absent.Antennule ( Fig.1B ) 5-segmented; length 164 Μm; armature formula: 6, 3, 4, 1, 12 + ae; first segment with integument separated from internal tissues. Antenna ( Fig. 1C ) 3-segmented; proximal segment unarmed (not figured); middle segment (basis) swollen, tapering distally, ornamented with surface pits; terminal claw lacking ornamentation; total length 196 Μm; middle segment length 140 Μm; terminal claw length 56 Μm. Parabasal papilla ( Fig. 3A ) tapering, hook-like knob, with wrinkled surface. Oral cone robust. Mandible ( Fig. 1D ) slender, tapering distally, with three sharp teeth distally. Maxillule ( Fig. 1E ) bilobate; both lobes armed with two sharp tapering processes. Maxilla ( Fig. 1F ) 4-segmented; proximal segment unarmed; second segment swollen, with one proximal seta on medial margin; third segment rod-like, elongated, with one distal seta; terminal segment small, with one small seta and bifid claw. Maxilliped absent.

Leg 1 ( Fig. 2A ) biramous; protopod fused with trunk, bearing one inner fine spine and one outer seta; exopod indistinctly 2-segmented, exp-1 with one outer seta, exp-2 with two distal setae; endopod 1-segmented, with one distal seta; protopod length 36 Μm; exopod length 26 Μm; endopod length 15 Μm. Leg 2 ( Fig. 2B ) biramous; protopod fused with trunk, bearing one plumose outer seta; exopod indistinctly 2-segmented, exp-1 with one outer seta ornamented with fine hairs, exp-2 with one inner and three distal setae; endopod 1-segmented, with two distal setae; protopod length 31 Μm; exopod length 44 Μm; endopod length 20 Μm. No variation noted in setation of legs 1 and 2. Protopod and rami of legs 1 and 2 ( Fig. 2A, B ) ornamented with crescentic rows of blunt spinules on surface. Intercoxal sclerites of both legs incorporated into body. Leg 3 ( Fig. 2C ) represented by two plumose setae carried on cylindrical process laterally at midlength. Leg 4 ( Fig. 2D ) comprising two plumose setae arising from subsurface papilla located 20% of length from end of trunk, respectively.

Male

Unknown.

REMARKS

Hatschekia maculatus n. sp. is characterized by the possession of well-developed posterolateral lobes on the trunk, and by having a cephalothorax and trunk of very similar width, as in H. cernae , a widely distributed species on epinepheline hosts (groupers) (Nunes-Ruivo 1954; Shiino 1957; Capart 1959; Jones 1985). In addition to the similar body shape, these two species also show a clear space separating the integument over the body surface from the underlying internal tissues, as in several other species such as H. flatti Uma Devi & Shyamasundari, 1980 , and both have caudal rami that are distinctly longer than wide ( Shiino 1957). They differ in many details such as the segmentation of the antennules which were described as indistinctly-segmented by Nunes- Ruivo (1954) but as 4-segmented by Shiino (1957), compared to 5-segmented in H. maculatus n. sp. Differences in legs 1 and 2 include: the endopod of leg 1 in the new species is 1-segmented and carries a single apical seta, whereas it is 2-segmented and bears 2 apical setae in H. cernae ; the exopod of leg 2 carries 4 setal elements on the distal segment in the new species compared to only 2 in H. cernae (Nunes-Ruivo 1954; Shiino 1957). The form of the posterolateral processes on the rear margin of the trunk is very distinctive – no other Hatschekia species has processes of this form, with a wider basal part carrying a narrow conical distal part with wrinkled cuticular surface.

Figures

FIG. 1. — Hatschekia maculatus n. sp. female: A, habitus, dorsal; B, antennule; C, antenna; D, mandible; E, maxillule; F, maxilla. Scale bars: A, 250 μm; B, C, F, 50 μm; D, E, 25 μm.

FIG. 2. — Hatschekia maculatus n. sp. female: A, leg 1; B, leg 2; C, leg 3; D, leg 4; E, posterior part of trunk, ventral. Scale bars: A-D, 25 μm; E, 50 μm.

FIG. 3. — A, Hatschekia maculatus n. sp.parabasal papilla,ventral (arrowed);B, C, Hatschekia cyanopodus n. sp.; B, parabasal papilla, ventral (arrowed); C, genital complex and abdomen, ventral; D, detail showing paired tuberculate processes (arrowed), ventral. SEM micrographs.