Cardiodectes bertrandi, Uyeno, Daisuke & Nagasawa, Kazuya, 2010

Uyeno, Daisuke & Nagasawa, Kazuya, 2010, Three new species of the family Pennellidae (Copepoda: Siphonostomatoida) from gobiid fishes (Actinopterygii: Perciformes) in coastal waters of the western Pacific Ocean, Zootaxa 2687, pp. 29-44 : 38-42

Cardiodectes bertrandi n. sp.

( Figs 8–10 )

Type material. Holotype, female ( MNHN –Cp 6047), ex Eviota sp. ( Perciformes : Gobiidae ), Lagoon of Ouvea (20°35’N, 166°26’E), Loyalty Islands, South Pacific Ocean, New Caledonia; 15 m depth; 20 December 2009 by D. Uyeno. Paratype, 1 female ( NSMT –Cr 21195), ex Eviota sp., Lagoon of Ouvea (20°35’N, 166°26’E), Loyalty Islands, South Pacific Ocean, New Caledonia; 15 m depth; 20 December 2009 by D. Uyeno.

Description of postmetamorphic adult female. Body ( Fig. 9 A, B) 2183–2579 (2381 ± 280) long (n = 2), comprising large cephalothorax, neck region and trunk. Cephalothorax ( Figs 9 C, D, 10A) semitriangular in dorsal view, shorter than wide [693–1024 (858 ± 234) × 928–1034 (981 ± 75)], bearing pair of anterior small lobes, expanded laterally forming pair of round large lobes; anterior process nodular and branched. Neck region ( Figs 9 D, 10A) narrow, bearing 2 tubercles. Trunk ( Fig. 9 A, B) broad, fabiform, longer than wide [1268–1503 (1385 ± 166) × 954–1085 (1020 ± 92)], slightly constricted at middle level. Egg sacs ( Fig. 8 A, B) uniseriate, coiled, protruding from oviduct orifices situated on posterolateral margins.

Antennule ( Fig. 10 B) on anterodorsal surface of cephalothorax; segmentation indistinct, carrying 8 setae along anterior margin; distal tip bearing 7 setae, 2 of which sharing common base, and 1 aesthetasc. Antenna ( Fig. 10 C) located posterior to antennules, 3-segmented, chelate, typical pennellid; proximal segment with chitinous, longitudinal ridge; middle segment bearing pointed projection on distal tip of inner margin and short chitinous, central ridge; terminal segment claw-like without armature. Mouth tube located on anterior part of ventral surface of cephalothorax. Maxillule ( Fig. 10 D) knob-like, situated on side of mouth tube, armed with 2 sharp, tapered processes on distal tip and attenuate process at base. Maxilla ( Fig. 10 E) 3- segmented, located closely behind of maxillule; proximal segment bearing single distal sharp process on inner margin, ornamented with small spinules around distal margin of posterior surface; middle segment carrying small spinules on distal part of posterior surface; terminal segment almost covered with small spinules on anterior surface. Maxilliped absent.

Legs 1 to 2 ( Fig. 10 F, G) biramous, situated centrally on cephalothorax ( Fig. 10 A). Leg 3 ( Fig. 10 H) uniramous, situated on posterior base of knob on neck region, separated from preceding legs by long gap ( Fig. 10 A); endopod absent. Armature formula of all three legs as follows:

Protopod Exopod Endopod

Leg 1 1–1 1–1; 7 0–0; 7

Leg 2 1–0 1–1; 7 0–0; 7

Leg 3 0–0 0–0; 6 ―

Anterior side of legs 1 to 3 pressed against ventral surface of each pediger. Protopod of legs 2 to 3 connecting by membranous structures to intercoxal sclerites.

Attachment site. The cephalothorax and neck region of copepod were embedded under the skin, near the pectoral fin of the host ( Fig. 8 A, B).

Remarks. As stated above, two groups, ‘medusaeus’ group and ‘rubosus’ group have been recognized in the genus Cardiodectes by the presence or absence of the abdomen ( Izawa 1970; Bellwood 1981). The new species, C. bertrandi n. sp., lacks an abdomen and thus is also assigned to the ‘rubosus’ group. The new species bears a pair of small anterior lobes concealed under the nodular processes and a pair of large posterior lobes on the cephalothorax ( Fig. 10 A), while both these pairs of lobes in C. asper n. sp. ( Fig. 6 A, B), C. hardenbergi , C. rotundicaudatus , C. rubosus and C. spiralis are large. Cardiodectes krishnai differs from the new species by having a trunk about 5 times as long as wide versus less than two times ( Fig. 9 A, B). The new species resembles C. boxshalli but differs in the following characters: a cephalothorax without a pair of large processes, protopods of legs 2 to 3 not connected to the intercoxal sclerites, and leg 3 situated on the neck region and separated from preceding legs by long gap.

Etymology. The specific name of the new species, bertrandi , is dedicated to Dr. Bertrand Richer de Forges, an outstanding carcinologist in New Caledonia, who assisted with the collection of the specimens.

Figures

FIGURE 6. Cardiodectes asper n. sp., female, holotype NSMT – Cr 21193. A, cephalothorax with digitiform processes removed, ventral, p 1 = leg 1, p 2 = leg 2, p 3 = leg 3; B, cephalothorax with digitiform processes removed and neck region, lateral, p 1 = leg 1, p 2 = leg 2, p 3 = leg 3; C, anterior part of cephalothorax with digitiform processes removed, dorsal; D, antennules, antennae and rostrum; E, antennule, posterior; F, antenna, anterior; G, maxillule; H, maxilla, anterior. Scale bars: A, B, D, 700 μm; C, 300 μm; E, H, 20 μm; F, 30 μm; G, 15 μm.

FIGURE 8. Cardiodectes bertrandi n. sp., female. A, a specimen of Eviota sp. carrying the holotype (MNHN – Cp 6047); B, a specimen of Eviota sp. carrying a paratype (NSMT – Cr 21195). Scale bars: A, 2000 μm; B, 1000 μm.

FIGURE 9. Cardiodectes bertrandi n. sp., female, holotype MNHN – Cp 6047. A, habitus, dorsal; B, habitus, lateral; C, cephalothorax and neck region, dorsal; D, cephalothorax and neck region, ventral. Scale bars: A, B, 1000 μm; C, D, 500 μm.

FIGURE 10. Cardiodectes bertrandi n. sp., female, holotype MNHN – Cp 6047. A, cephalothorax with digitiform processes removed and neck region, ventral (drawn from a paratype, NSMT – Cr 21195), p 1 = leg 1, p 2 = leg 2, p 3 = leg 3; B, antennule, posterior; C, antenna, posterior; D, maxillule; E, maxilla, anterior; F, leg 1 (drawn from a paratype, NSMT – Cr 21195); G, leg 2 (drawn from a paratype, NSMT – Cr 21195); H, leg 3 (drawn from a paratype, NSMT – Cr 21195). Scale bars: A, 400 μm; B, F, G, H, 30 μm; C, D, E, 20 μm.