Cardiodectes vampire Aneesh & Helna & Kumar & Maran 2023, sp. nov.
Creators: name: Aneesh, Panakkool Thamban
name: Helna, Ameri Kottarathil
name: Kumar, Appukuttannair Biju
name: Maran, Balu Alagar Venmathi
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Copepoda
Siphonostomatoida
Pennellidae
Cardiodectes
Cardiodectes vampire

description: Cardiodectes vampire sp. nov.
urn:lsid:zoobank.org:act: A2C1366C-5022-4837-A0BF-037960BB425A
(Figures 1–9)
Materials examined. 28 ♀♀
Holotype. 1♀ (12 mm, excluding egg strings), from Chlorophthalmus corniger Alcock, 1894 (TL 37 cm) from the Arabian Sea, off Neendakara, Kollam district, Kerala, India (Reg. No. ZSI / WGRC /IR/ INV/ 25193) coll. PT Aneesh, 13 th November 2018.
Paratypes. Same information as the holotype with the following measurements and registration details: 1♀ (11.5 mm, excluding egg strings), (Reg. No. ZSI / WGRC /I. R./INV/25194) coll. PT Aneesh, 22 nd November 2018; 1♀ (11 mm, excluding egg strings), (Reg. No. ZSI / WGRC /IR/INV/25195) coll. PT Aneesh, 24 th November 2018; 1♀ (11 mm, excluding egg strings), (Reg. No. ZSI / WGRC /IR/INV/25196); 1♀ (12 mm, excluding egg strings), (Reg. No. ZSI / WGRC /IR/INV/25197); 1♀ (11.5 mm, excluding egg strings), (Reg. No. ZSI / WGRC /IR/INV/25198); 1♀ (11 mm, excluding egg strings), (Reg. No. CAH /INV/ COP 0217), 1♀ (10.8 mm, excluding egg strings), (Reg. No. CAH /INV/ COP 0218); 1♀ (11.7 mm, excluding egg strings), (Reg. No. CAH /INV/ COP 0219) coll. PT Aneesh, 26 th November 2018.
Non-types: 17 ♀♀ (size range 10.8–12 mm excluding egg strings) (Reg. No. CAH /INV/ COP 0200–216) coll. PT Aneesh, 26 th November 2018.
Description
Post-metamorphic adult ovigerous female: Body (Figs 1–4) slender, 11–12 mm (excluding egg strings) long, consisting of cephalothorax, short neck and long trunk. Cephalothorax (Figs. 2–4, 5A–D), 1.2 times wider than long, bearing two pairs of lateral lobes, one large median lobe posteriorly and pair of ventral lobes; posterior lateral lobes larger with irregular ridges, extended ventrolaterally between first neck lobe. Cephalothorax anteriorly bearing small nodular, tightly packed and branching processes; anterior processes extended between anterior half of cephalothorax dorsally and posterior lobes ventrally (Figs. 2–4, 5A–D). Neck region (Figs. 2–4, 5A, D–F) narrow, about 0.1 time as total body length, bearing pair of lobes. Trunk (Figs. 2–4, 9) 3.15 times as long as wide (8.5 mm L; 2.7 mm W), 70% as TL, oval with greatest width at posterior, posterior margin convex. Paired gonopores located sub-terminally.
Egg strings long (maximum 41 mm), uncoiled (Figs 1, 2C); eggs uniseriate (Figs 1, 2C, 9D). Number of eggs per string ranged from 550 to 620, depending on string length. Caudal rami absent.
Rostrum, antennules, and antennae situated closely on anterodorsal surface of cephalothorax (Fig. 6). Antennule (Fig. 6A, 7A–C) unsegmented, bearing around 35 setae mainly on anterior terminal part and lateral margins; distal tip with 1 long aesthetasc. Antenna (Fig. 6B, 7D–F) 3-segmented, chelate, typical pennellid form; proximal segment with highly sclerotized ridge on inner surface; segment 2 with inner medial pointed projection. Mouth tube, maxillule, and maxilla located on anterior part of ventral surface of cephalothorax (Fig. 4B). Maxillule (Fig. 6C) knoblike, bilobate; lobe 1 having 2 simple processes and lobe 2 with 1 process. Maxilla (Fig. 6D) 2-segmented; proximal segment with pointed anteromedial process; terminal segment indistinctly 2-segmented, with fine terminal spinules. Maxilliped absent.
Legs, 3 pairs, legs 1 and 2 (Figs. 6E,F, 8) biramous, present centrally on cephalothorax (Fig. 5E, H). Leg 3 (Figs. 5G, 6G) uniramous, situated behind lobe on neck (Figs. 5D–G). Rami of all legs 2-segmented. Leg 3 bearing protopod separated from intercoxal sclerite. Armature formula as follow (Roman numerals indicate spines and Arabic numerals indicate plumose setae).
TABLE.
Size. Matured post-metamorphic adult female: 11–12 mm (total length excluding egg strings).
Intra-specific variation. No significant intra-specific variation was observed other than the length.
Colour. Fresh specimens are translucent dark red colour.
Host. Chlorophthalmus corniger Alcock, 1894 (Chlorophthalmidae).
Attachment site. The cephalothorax and neck region of Cardiodectes vampire sp. nov. were embedded in the host’s body musculature, while its trunk and egg sacs were freely hanged (see Fig. 1).
Ecological remarks. In this study, out of 45 host fish (C. corniger; TL 11–14 cm) examined, 26 were found to be infested with Cardiodectes vampire sp. nov. with a prevalence of 57.7%. A total of 78 pennellids were recovered from these 26 host fish, with intensity ranging from 2 to 6 (mean intensity = 3). All recovered females were post-metamorphic adults as evident from the presence of fully filled/filling/empty egg sacs. Mature post-metamorphic adult females of C. vampire sp. nov. recovered from the external body surface of the host fish C. corniger. In the body surface, it is found penetrating on the upper and lower jaws (Fig. 1A), on the dorsal and dorsolateral body surface between eyes and dorsal fin (Fig. 1B), in the dorsal surface of the host’s head, which induced a swelling on the head (Fig. 1C) and lateral body surface (Fig. 1D). The cephalothorax and neck region of the parasites embedded in the host’s body musculature and the trunk and egg sacs are freely hanged. Further, the cephalothorax of live/fresh parasites was dark reddish due to host blood feeding (see fig. 2).
Distribution. Known only from the type locality, Neendakara, Kerala coast of the Arabian Sea, India.
Etymology. The specific name is derived from the word ‘vampire’ means a mythical creature that subsists by feeding on the blood of the living; noun apposition.
Diagnosis: The diagnostic features of Cardiodectes vampire sp. nov., include: trunk 3.15 times as long as wide; extremely long (3.5 times as long as total body length) and uncoiled egg sacs; difference in the armature of legs 1–3; comparatively longer trunk (0.7 times as long as total body length).
Remarks
The new species, Cardiodectes vampire, clearly belongs to the ‘‘ rubosus ’’ species group as it lacks an abdomen and can be distinguished from other members of the genus by the combination of the following characteristic features: trunk 3.15 times as long as wide; extremely long and uncoiled eggsacs; the difference in the armature of legs 1–3; comparatively long trunk (0.7 times as long as total body length).
Species of Cardiodectes are known from, North Pacific Ocean, Japan (Shiino 1958; Uyeno and Nagasawa 2010), off Kadone in Sagami Bay (Izawa 1970), Indo-Pacific (Gnanamuthu 1951; Sebastian 1968; Pillai 1985), Salmon Island, Graham Land (Leigh-Sharpe 1934), New Guinea (Bellwood 1981), North Atlantic Ocean and Mediterranean Sea (Jungersen 1911; Wilson 1917; Capart 1953; Hogans 2017), Great Barrier Reef, Australia (Uyeno 2013), South Pacific Ocean, New Caledonia (Uyeno and Nagasawa 2010), Java Sea (Markevich 1936), off Jamaica, the Carribean part of Central America (Bellwood 1981; Suárez-Morales et al. 2022) (see Table 1).
In relation to host, the family Gobiidae is parasitized with 5 species of Cardiodectes, followed by Myctophidae (4 species), Engraulidae (2 species) and Scaridae (2 species), other families such as Apogonidae, Chlorophthalmidae, Phosichthyidae and Serranidae were found with 1 species (see Table 1).
Species of Cardiodectes, shows different levels of host specificity. Out of five species of Cardiodectes known from Gobiid fishes, four species are recorded only from the type host: C. asper from Trimma grammistes; C. bellwoodi from Istigobius nigroocellatus; C. bertrandi from Eviota sp.; C. rotundicaudatus from Suruga fundicola and on the other hand C. shini is recorded from following four species of host fishes Pleurosicya micheli, Eviota sebreei, Eviota sp., and Priolepis sp. Similarly, two Cardiodectes species are known from engraulid fishes; C. anchorellae recorded from following three fishes, Stolephorus tri, Stolephorus indicus and Thryssa hamiltonii; and C. hardenbergi known only from the type host Encrasicholina heteroloba (Izawa, 1970; Bellwood, 1981; Uyeno, 2013).
Another four species are recorded from the fishes of the family Myctophidae. Among them C. bellottii is recovered from following five hosts; Hygophum benoiti, Notoscopelus caudispinosus, Benthosema glaciale, Diaphus rafinesquii, Myctophum sp. and remaining three Cardiodectes species known only from its type host; C. cristatus from Diaphus suborbitalis; C. frondosus from Dasyscopelus spinosus; and C. longicervicus from Dasyscopelus asper (Izawa, 1970; Bellwood, 1981; Uyeno, 2013).
Cardiodectes boxshalli and the recently described C. roatanensis are known only from their type host such as Nicholsina usta and N. ustis, respectively both are from the family Scaridae (Uyeno, 2013; Sua´rez-Morales et al. 2022). Similar to that the remaining four species of Cardiodectes, including the new species described here are recorded only from its type host; C. rubosus from Apogen sp. (Apogonidae), C. vampire sp. nov. from C. corniger (Chlorophthalmidae), C. krishnai from Vinciguerria lucetia (Phosichthyidae) and C. spiralis from Pseudanthias tuka (Serranidae) (Sebastian, 1968; Pillai, 1985; Uyeno, 2013).
With the description of Cardiodectes vampire sp. nov., the total number of species under the genus are currently seventeen. By the absence of an abdomen, the new species can be well separated from ‘ medusaeus ’ group. Cardiodectes vampire sp. nov. differs from C. asper, C. bellwoodi, C. bertrandi, C. boxshalli, C. roatanensis, C. spiralis, and C. shini by having a trunk 3.15 times as long as wide (vs. twice or less than twice as long as wide) (Leigh-Sharpe 1934; Markevich 1936; Sebastian 1968; Izawa 1970; Bellwood 1981; Uyeno and Nagasawa 2010; Uyeno 2013; Suárez-Morales et al. 2022).
Remaining four species, C. hardenbergi, C. krishnai, C. rotundicaudatus, and C. rubosus having a trunk greater than twice as long as wide. Cardiodectes krishnai can be well distinguished from C. vampire sp. nov. by having a trunk about 5 times as long as wide (vs. trunk 3.15 times as long as wide) (Sebastian 1968; Bellwood 1981). The following three species C. hardenbergi, C. rotundicaudatus, and C. rubosus can be separated from the new species C. vampire by having the body 1.7 times longer than cephalothorax and neck combined (vs. 2.4 times longer than cephalothorax and neck combined). Furthermore, in C. rubosus four pairs of legs are present (vs. three pairs in C. vampire). Both C. hardenbergi and C. vampire sp. nov. possessing the uncoiled eggsacs, however in C. vampire sp. nov. it is extremely long (3.5 times longer than total body length).
description: Published as part of Aneesh, Panakkool Thamban, Helna, Ameri Kottarathil, Kumar, Appukuttannair Biju & Maran, Balu Alagar Venmathi, 2023, A new species of Cardiodectes Wilson C. B., 1917 (Copepoda: Siphonostomatoida Pennellidae) from Spinyjaw greeneye, Chlorophthalmus corniger Alcock, 1894 off the Indian Ocean, pp. 277-291 in Zootaxa 5369 (2) on pages 278-289, DOI: 10.11646/zootaxa.5369.2.7, http://zenodo.org/record/10146813