Cardiodectes shini, Uyeno, Daisuke, 2013

Uyeno, Daisuke, 2013, Two new species of Cardiodectes Wilson, 1917 (Copepoda: Siphonostomatoida: Pennellidae) from gobiid fishes (Actinopterygii: Perciformes) in the western Pacific Ocean, Zootaxa 3664 (3), pp. 301-311 : 306-309

Cardiodectes shini n. sp.

( Figs 1 C, D, 4–5)

Type material. Holotype: female (NSMT–Cr 22332), ex Pleurosicya micheli Fourmanoir ( Perciformes : Gobiidae ), Oura Bay (26°31’N, 128°4’E), Okinawa-jima Island, Ryukyu Islands, North Pacific Ocean, Japan, 33 m depth, 29 April 2012, reg. D. Uyeno and S. Nishihira. Paratypes: 3 females (NSMT–Cr 22333), ex Eviota sp., off Zatsun (26°49’N, 128°14’E), Okinawa-jima Island, Ryukyu Islands, East China Sea, Japan, 15 m depth, 27 June 2010, reg. D. Uyeno; 1 female (RUMF–ZC– 2391), ex P. m i c h e l i, Oura Bay (26°31’N, 128°4’E), Okinawa-jima Island, Ryukyu Islands, North Pacific Ocean, Japan, 31 m depth, 17 April 2012, reg. D. Uyeno and S. Nishihira; 1 female (NSMT–Cr 22334), ex P. micheli, Oura Bay (26°31’N, 128°4’E), Okinawa-jima Island, Ryukyu Islands, North Pacific Ocean, Japan, 30 m depth, 29 April 2012, reg. D. Uyeno and S. Nishihira; 2 female (NSMT–Cr 22335), ex Eviota sebreei Jordan & Seale ( Perciformes : Gobiidae ), Oura Bay (26°31’N, 128°4’E), Okinawa-jima Island, Ryukyu Islands, North Pacific Ocean, Japan, 28 m depth, 29 April 2012, reg. D. Uyeno and S. Nishihira; 1 female (RUMF–ZC– 2392), ex Priolepis sp. ( Perciformes : Gobiidae ), off Kyoda (26°32’N, 127°57’E), Nago Bay, Okinawa-jima Island, Ryukyu Islands, East China Sea, Japan, 33 m depth, 16 August 2012, reg. N. Shirakawa.

Description of postmetamorphic adult female. Body ( Fig. 4 A, B) 2705 long, comprising cephalothorax, neck and trunk. Cephalothorax ( Fig. 4 C, D, E) wider than long 725 × 917, bearing nodular and branching anterior processes on distal part of ventral surface and a pair of anterior digitiform lobes, as well as an expanded posterolateral pair of round lobes; anterior processes covering anterior half of cephalothorax ( Fig. 4 A, B, C). Neck region ( Fig. 4 C, D, E) narrow, bearing pair of lobes, and bending through 90o. Trunk ( Fig. 4 A, B) less than twice as long as wide 1900 × 980, oval with greatest width at posterior ¾ and with convex posterior margin. Egg sac spiral ( Fig. 4 A) uniseriate, originating at posterior lateral genital apertures.

Rostrum, antennules, and antennae situated closely on anterodorsal surface of cephalothorax ( Fig. 5 A). Rostrum ( Fig. 5 A) hemispherical, situated between bases of antennules. Antennule ( Fig. 5 A, C) unsegmented, bearing 8 setae mainly on anterior margin; distal tip bearing 8 setae, 2 bifurcate setae, and 1 aesthetasc. Antenna ( Fig. 5 A, D) 3-segmented, chelate, typical pennellid in form; proximal segment with highly sclerotized ridge on surface; middle segment bearing inner medial pointed projection; terminal claw with 1 small basal seta on posterior surface. Mouth tube, maxillule, and maxilla located on anterior part of ventral surface of cephalothorax ( Fig. 5 B). Maxillule ( Fig. 5 E) in form of bilobate knob, located lateral to base of mouth tube; each knob bearing 2 and 1 simple blunt processes. Maxilla ( Fig. 5 B, F) 2-segmented; proximal segment with pointed anteromedial process; terminal segment indistinctly 2-segmented by constriction, covered with fine spinules at middle. Conspicuous bilobed process present between bases of maxillae ( Fig. 5 B). Maxilliped absent.

Both legs 1 and 2 ( Fig. 5 G, H) biramous, present centrally on cephalothorax ( Fig. 5 D, E). Leg 3 ( Fig. 5 I, J) uniramous, situated behind lobe on neck. Armature formula of all three legs as follows:

Leg 3 bearing protopod separated from intercoxal sclerite.

Variability of female morphology. The morphology of the female paratypes is as in the holotype. The measurements of the type series (n = 9) are as follows: body length 2038–2767 (2494 ± 253); cephalothorax length 495–840 (643 ± 98); cephalothorax width 616–957 (808 ± 115); trunk length 1462–1986 (1813 ± 199); trunk width 870–1250 (1050 ± 116).

Attachment site. The cephalothorax and neck region of the copepod were embedded in the host’s head musculature, while its trunk and egg sacs stick out into the water ( Fig. 1 C, D).

Remarks. As C. bellwoodi n. sp., C. shini n. sp. is assigned to the ‘rubosus’ group because of the absence of a defined abdomen (see Izawa 1970; Bellwood 1981). Cardiodectes shini n. sp. differs from C. hardenbergi , C. krishnai , C. rotundicaudatus , and C. rubosus by having a trunk less than twice as long as wide (vs. more than twice as long as wide, Leigh-Sharpe 1934; Markevich 1936; Sebastian 1968; Izawa 1970; Bellwood 1981). Of the remaining five species, C. asper , C. bellwoodi n. sp, C. bertrandi , C. boxshalli , and C. spiralis , only C. asper shares the following characters with C. shini n. sp.: the neck region bends through 90o in the middle and bears a well-developed pair of lobes, and leg 3 is located on the posterior part of the base of the neck lobes (Bellwood 1981; Uyeno & Nagasawa 2010). These two species resemble each other, but C. shini n. sp. is distinguishable by the presence of the well-developed, bilobed process between the bases of the maxillae and by the cephalothorax bearing two pairs of lobes (vs. without the well-developed bilobed process and the cephalothorax with 3 pairs of lobes (see Uyeno & Nagasawa 2010)). In addition, legs 1 and 2 of C. shini n. sp. have protopods which are not separated from their intercoxal sclerites (vs. separated in C. asper (see Uyeno & Nagasawa 2010)).

Etymology. The specific name of the new species, shini , is after Shin “Snufkin” Nishihira, a President of Diving Team Snuck Snufkin, who is the best explorer of the Oura Bay, Okinawa-jima Island.

Newly established Japanese name for Cardiodectes shini n. sp. Shin-no-kanzashi.

Figures

FIGURE 1. Postmetamorphic adult females of Cardiodectes bellwoodi n. sp. and C. shini n. sp. attached to their hosts. A, two specimens of Istigobius nigroocellatus (Günther) carrying the type series of C. bellwoodi n. sp.; B, a holotype (AMP. 90285) of C. bellwoodi n. sp. attached to the host; C, a specimen of Pleurosicya micheli Fourmanoir carrying a holotype (NSMT – Cr 22332) of C. shini n. sp.; D, a specimens of Eviota sebreei Jordan & Seale carrying paratypes (NSMT – Cr 22335) of C. shini n. sp. Scale bars: A, 10 mm; B, C, D, 3 mm.

FIGURE 4. Cardiodectes shini n. sp., postmetamorphic adult female, holotype, NSMT – Cr 22332. A, habitus, dorsal; B, same, lateral; C, cephalothorax and neck region, ventral; D, cephalothorax and neck region with digitiform processes removed, ventral, mx 2 = maxilla, p 1 = leg 1, p 2 = leg 2, p 3 = leg 3; E, same, lateral, a 1 = antennule, a 2 = antenna. Scale bars: A, B, 1000 μm; C, D, 500 μm; E, 400 μm.

FIGURE 5. Cardiodectes shini n. sp., postmetamorphic adult female, holotype, NSMT – Cr 22332. A, anterior part of cephalothorax with antennule, antennae and rostrum; B, oral cone, maxillae and bilobed process; C, right antennule, anterior; D, right antenna, anterior; E, left maxillule; F, right maxilla, anterior; G, left leg 1 with intercoxal sclerite; H, right leg 2 with intercoxal sclerite; I, right leg 3 protopod with intercoxal sclerite; J, right leg 3 exopod. Scale bars: A, B, 50 μm; C, D, J, 10 μm; E – I, 20 μm.