Hatschekia louti, 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 : 388-390

Hatschekia louti n. sp.

Hatschekia sp. 8 – Justine et al. 2010a: fig. 1G.

TYPE HOST. — Variola louti (Forsskål, 1775) ( Perciformes : Serranidae ).

ADDITIONAL HOST. — Variola albimarginata Baissac, 1952 ( Perciformes : Serranidae ).

TYPE LOCALITY. — Récif Le Sournois, off coast of Nouméa, New Caledonia (22°19’32’’S, 166°27’37’’E).

ETYMOLOGY. — The specific name of the new species, louti , is treated as a noun in apposition and is based on its host.

MATERIAL EXAMINED. — Holotype female (MNHN- IU-2013-4008) dissected on 9 slides. 16 ♀♀ undissected paratypes, from Variola louti [JNC 1208B], Récif Le Sournois , off coast of Nouméa, New Caledonia (22°19’32’’S, 166°27’37’’E), coll. J.-L. Justine, 27.VII.2004. 6 ♀♀ undissected in MNHN-IU-2013-4009, 1 ♀ undissected in NHMUK 2012.1298 , 2 ♀♀ undissected in MABIK CR00179940 - CR00179941 .

ADDITIONAL MATERIAL. — 1 ♀ from Variola albimarginata [JNC1209A], Récif Le Sournois , off coast of Nouméa, New Caledonia (22°19’32’’S, 166°27’37’’E), coll. J.- L. Justine, 27.VII.2004. ( NHMUK 2012 . 1299) ;

4 ♀♀ from V. albimarginata [JNC1247B], Récif Le Sournois , off coast of Nouméa, New Caledonia (22°19’32’’S, 166°27’37’’E), coll. J.-L.Justine, 15.IX.2004. ( NHMUK 2012.297 - 300 ) ;

3 ♀♀ from V. louti [JNC1353B], Passe de Dumbéa, New Caledonia, coll. J.-L. Justine, 28.IX.2004. (MNHN- IU-2013-4010).

DESCRIPTION

Female

Total body length 570-660 Μm (n = 8, mean = 620 Μm) excluding caudal rami. Cephalothorax

( Fig. 6A ) wider than long (125 × 188 Μm), with straight frontal margin, protruding lateral margins and rounded posterior margin; dorsal surface with distinct chitinous markings in form of “m-shape”, bar in mid-line extending beyond posterior tips of curved lateral bars and divided at posterior end; curved lateral bars with anterior side branch near antero-lateral angle of cephalothorax.Trunk ( Fig.6A ) fusiform, longer than wide (498 × 155 Μm), with greatest width about at level of insertion of third legs; trunk bearing conspicuous paired tapering processes at posterolateral corners, each slightly outwardly curved and terminating in rounded knob-like tip ( Fig. 7F ). Urosome ( Fig. 7F ) excluding caudal ramus shorter than wide (41 × 63 Μm), comprising fused genital complex and abdomen ( Fig. 7F ). Caudal ramus ( Fig. 7F ) elongate, longer than wide (27 × 13 Μm), with five naked setae.

Rostrum absent.Antennule ( Fig.6B ) 4-segmented; length 121 Μm; armature formula: 8, 10, 1, 13 + ae. Antenna ( Fig. 6C ) 3-segmented; proximal segment unarmed; middle segment (basis) swollen, tapering distally, ornamented with surface pits; terminal claw small, without armature; total length 97 Μm; middle segment length 81 Μm; terminal claw length 17 Μm. Parabasal papilla shrivelled, carrying apical process. Oral cone robust. Mandible ( Fig. 6D ) slender, rodlike, with five small blunt teeth. Maxillule ( Fig. 6E ) bilobate; both lobes armed with two sharp tapering processes. Maxilla ( Fig. 7A ) 4-segmented; proximal segment unarmed; second segment swollen, with one basal seta; third segment rod-like, elongated, with one distal seta; terminal segment small, with one small seta and bifid claw. Maxilliped absent.

Leg 1 ( Fig. 7B ) biramous; protopod bearing one inner spine and one fine outer seta; exopod indistinctly 2-segmented, exp-1 with one outer seta, exp-2 with three distal setae; endopod 2-segmented, enp-1 unarmed, enp-2 with one distal seta; protopod length 36 Μm; exopod length 26 Μm; endopod length 19 Μm. Leg 2 ( Fig. 7C ) biramous; exopod 2-segmented, exp-1 with one outer seta, exp-2 with one seta; endopod 1-segmented, with one distally small seta; protopod length 51 Μm; exopod length 30 Μm; endopod length 34 Μm. Protopod and rami of legs 1 and 2 ( Fig. 7B, C ) elongate and unornamented. Intercoxal sclerites of both legs elongate, unornamented and unmodified. Legs 3 and 4 ( Fig. 7D, E ) each represented by small lobe tipped with two simple setae, located laterally in middle and at three quarters length of trunk.

Male

Unknown.

REMARKS

Hatschekia louti n. sp. shares the possession of conspicuous paired processes at the posterolateral corners of the trunk with H. conifera Yamaguti, 1939 , although the processes have a shallower conical shape in the latter compared with the slender, slightly outward curving processes (terminating in a rounded, knob-like tip) of the new species. Hatschekia conifera was originally described on the basis of Japanese material taken from the host Pampus argenteus (Euphrasen, 1788) (as Stromateoides argenteus ) ( Yamaguti 1939). It was redescribed by Cressey (1968) who also described the male for the first time: his material was from Cubiceps caerulus Regan, 1914 caught off Chile. Kabata (1981) examined material of H. conifera from Brama japonica Hilgendorf, 1878 and relegated H. acuta Barnard, 1948 to synonymy with H. conifera . Jones (1985) confirmed this synonymy after re-examination of Barnard’s type material of H. acuta from Brama brama (Bonnaterre, 1788) (as Brama raii Bloch & Schneider, 1801 ) taken in South African waters, and after study of new material from Brama brama from New Zealand. So H. conifera is widely distributed in the Indo-Pacific and occurs on a variety of different hosts but it is well characterized and we found that H. louti n. sp. differs significantly from H. conifera in body shape, in the armature formula of the antennule, in the number of teeth on the mandible, and most obviously in the form of legs 1 and 2 and the armature formula of legs.

Hatschekia louti n. sp. has a very modified endopod on leg 2. In H. conifera the endopods of legs 1 and 2 are 2-segmented and carry six setal elements ( Cressey 1968) whereas in the new species leg 1 has a 2-segmented endopod with just a single apical seta while leg 2 has an enlarged unsegmented lobate endopod bearing a single minute seta. A similar enlarged endopod is present in leg 2 of H. becuni Jones & Cabral, 1990 but this species differs from H. louti n. sp. in lacking any processes on the trunk. The endopod is also broad in H. jonesi Uyeno & Nagasawa, 2010 but this ramus is 2-segmented and retains four setae in H. jonesi .

Figures

FIG. 6. — Hatschekia louti n. sp.female:A, habitus,dorsal;B, antennule;C, antenna;D, mandible;E, maxillule.Scale bars:A-C,50 μm; D, E, 25 μm.

FIG. 7. — Hatschekia louti n. sp. female: A, maxilla; B, leg 1; C, leg 2; D, leg 3; E, leg 4; F, posterior part of trunk, ventral. Scale bars: A, F, 50 μm; B-E, 25 μm.