Predorsal Vertebrae Research Articles

Two new species of the congrid eel genus Ariosoma (Anguilliformes, Congridae, Bathymyrinae) from Indian waters

Two new species have been described from Indian waters, based on the materials collected from Kochi coast, Arabian Sea, Gulf of Mannar and West Bengal coast along the Bay of Bengal. Ariosoma gracilesp. nov. is described, based on five specimens collected from the landings at Kalamukku Fishing Harbour, Arabian Sea. The new species is characterised by longer tail, 55.3–58.7% TL; dorsal-fin origin above pectoral-fin base; no dark or whitish bands on dorsal surface of head, ventral extremities of lower jaw and mid-portion with minute dark pigmentation patch; anus positioned well before the middle of total length; SO canal with 4 pores; 0 or 3 pores on ST canal; pre-dorsal vertebrae 9; pre-anal vertebrae 49–54; total vertebrae 140–142. Ariosoma gracilesp. nov. is closely related to Ariosoma dolichopterum and Ariosoma emmae by sharing similar morphometrics and pre-anal vertebral counts. However, it differs by having more total pores (132–135 vs. 121–129 in A. dolichopterum, 123–126 in A. emmae); fewer pre-anal pores (43–46 vs. 47–51 in A. dolichopterum, 50–53 in A. emmae); more pre-dorsal pores (9 vs. 5–9 in A. dolichopterum, 4–6 in A. emmae). Another new species, Ariosoma kannanisp. nov. is described on the basis of two specimens (157–171 mm TL) from Gulf of Mannar and one specimen (201 mm TL) collected from Shankarpur Fish Landing Centre, West Bengal. This species is similar to Ariosoma megalops, but readily differs by having smaller eyes, smaller interorbital distance and exhibits 10.8% genetic divergence from A. megalops from the Taiwan waters.

Discovery of a new Muraenichthys eel (Anguilliformes: Ophichthidae) from the Bay of Bengal, India, with its molecular characterization

Muraenichthys hibinoi sp. nov. is described herein based on two specimens collected from Shankarpur fishing harbor, West Bengal, India. The new species differs from Muraenichthys gymnopterus, Muraenichthys hattae, Muraenichthys longirostris, and Muraenichthys thompsoni by having less distance between the anus and the origin of the dorsal fin (61.8%–57.37% vs 73.8%–82% of HL). The new species has a close morphological affinity with M. gymnopterus and M. hattae with significant differences from both species. The new species differs from M. gymnopterus by having higher vertebral count, i.e., predorsal vertebrae (40– 41 vs 30), preanal vertebrae (50 vs 43), and total vertebrae (140–141 vs 130). The new species also differs from M. hattae, having fewer total vertebrae (141–142 vs 148–155) and fewer predorsal vertebrae (40–41 vs 48–53). The COI gene sequence of the new species has been generated and submitted to the NCBI database with accession number OP114397. The new species differs from all the available congeneric sequences of Myrophinae group available in NCBI or BOLD with K2P distances of 8.4% to 9.5%. Thus, both the genetic and morphometric data confirm the presence of a new species in Myrophinae from Indian waters.

Description of Two New Labeo (Labeoninae; Cyprinidae) Endemic to the Lulua River in the Democratic Republic of Congo (Kasai Ecoregion); a Hotspot of Fish Diversity in the Congo Basin

Labeo mbimbii, n. sp., and Labeo manasseeae, n. sp., two small-bodied Labeo species, are described from the lower and middle reaches of the Lulua River (Kasai ecoregion, Congo basin) in the Democratic Republic of Congo. The two new species are members of the L. forskalii species group and are genetically distinct from all other species of that clade. Morphologically they can be distinguished from central African L. forskalii group congeners except L. dhonti, L. lukulae, L. luluae, L. parvus, L. quadribarbis, and L. simpsoni in the possession of 29 or fewer (vs. 30 or more) vertebrae and from those congeners by a wider interpectoral, among other features. The two new species are endemic to the Lulua River and, although overlapping in geographical range and most meristic and morphometric measures, are readily differentiated by differing numbers of fully developed supraneural bones, predorsal vertebrae, snout morphology, and additional osteological features. The description of these two species brings the total of Labeo species endemic to the Lulua basin to three. The third endemic species, L. luluae, was previously known only from the juvenile holotype, but numerous additional specimens have now been identified. The cooccurrence of 14 Labeo species in the Lulua River, three of which are endemic, highlights this system as a hotspot of Labeo diversity in the Congo basin and across the continent.

A new short brown unpatterned moray eel (Anguilliformes, Muraenidae) from the southeast coast of India, Bay of Bengal

Gymnothorax tamilnaduensissp. nov., a new species of short brown unpatterned moray, is described, based on four specimens ranging from 272–487 mm total length collected from the trawl bycatch landings at Mudasalodai fish landing centre, off Cuddalore coast, Tamil Nadu, southeast coast of India. The new species is distinguished by the following combination of characters: origin of dorsal fin at middle of rictus and gill opening, anus just before mid-body, series of lines of small dark spots present on head and a single line of black spot-on mid-line of body, jaw pores with white rim, anal-fin margin whitish, 3 pre-dorsal vertebrae, 56–59 pre-anal vertebrae and 139–150 total vertebrae. The new species differs from its known Indian water congeners by having series of lines of small dark spots present on the head and a single line of black spots on the mid-line of the body (vs. absent in all the three congeners in India), serrated teeth (vs. smooth), jaw pores with white rim (vs. black to brown in others) and higher vertebral count (139–150 vs. 134–138 in others). Our morphological and molecular analyses show that the new species forms a distinct clade from its congeners and these data support the status as a new species.

A new congrid eel, Rhynchoconger randalli sp. nov. (Congridae: Anguilliformes), with a pentagonal pattern of vomer dentition from the Bay of Bengal, Indian waters.

A new species Rhynchoconger randalli sp. nov. is described herein on the basis of 2 specimens collected from Paradeep fishing harbor, Odisha, India along the Bay of Bengal from a depth of about 3640 meters. The pentagonal vomerine teeth pattern is unique among all the Rhynchoconger species described to date. The new species is characterized by predorsal vertebrae 78 and preanal vertebrae 2931. The new species closely resembles the recently described Rhynchoconger smithi, but differs in having a larger eye diameter (12.512.9% HL vs. 9.59.7% in R. smithi), smaller interorbital space (13.113.5% HL vs. 15.018.1 in R. smithi), lower dorsal-fin ray count before vent 4447 vs. 5458 in R. smithi, and unique pentagonal vomerine teeth pattern.

A new species of conger eel, Ariosoma (Congridae: Bathymyrinae), from the Bay of Bengal, India.

Ariosoma bengalense sp. nov. is described on the basis of two specimens having total length (TL) 216304 mm, collected from the northern part of the Bay of Bengal, India. The new species is characterized by the dorsal-fin origin positioned above the gill-opening margin and above the 9th lateral-line pores, supratemporal pore absent, 910 predorsal vertebrae; 4649 preanal vertebrae and 146149 total vertebrae. The new species most closely resembles the Indian species Ariosoma gnanadossi, the new species differs from A. gnanadossi having the snout length (SL) longer than eye diameter (snout length 1.42.0 in eye diameter) vs. snout length almost equal to the eye diameter in A. gnanadossi. Further, the new species has translucent pectoral fins vs. black pectoral fins in Ariosoma gnanadossi. The new species differs from four of the seven species reported from India: Ariosoma majus, A. melanospilos, A. maurostigma and A. indicum with absence of supratemporal pores vs. three in all the species mentioned.

Notoraja hesperindica sp. nov., a new colorful deep-sea softnose skate (Elasmobranchii, Rajiformes, Arhynchobatidae) and first generic record from the western Indian Ocean

A new deep-sea softnose skate, Notoraja hesperindica, is described based on six specimens caught in 1230–1600 m depths off southern Mozambique and northwestern Madagascar in the western Indian Ocean. The new species is a medium-sized species of Notoraja Ishiyama, 1958 reaching a total length of at least 539 mm. It is the only Notoraja species known from the western Indian Ocean and differs from most congeners in the intense dark blue-grayish coloration. The only congeners with similarly vibrant coloration are Notoraja azurea McEachran & Last, 2008 from off southern Australia and Notoraja sapphira Seret & Last, 2009 from the Norfolk Ridge (Coral Sea and Tasman Sea), which differ from the new species in a shorter and more obtusely angled snout, a shorter head, a shorter disc, and smaller dorsolateral tail thorns, as well as more predorsal tail and total predorsal vertebrae and more pectoral-fin radials. The large dorsolateral tail thorns also distinguish the new species from most congeners except for the eastern Pacific Notoraja martinezi Concha, Ebert & Long, 2016, which has even larger, randomly patterned dorsolateral tail thorns that give the tail a barbedwire-like appearance. This congener further differs from N. hesperindica sp. nov. in the absence (vs. presence) of malar thornlets, fewer median tail thorns, a shorter snout, more tooth rows in upper and lower jaws, and more pectoral radials. A key to the species of Notoraja in the Indian Ocean is provided.

A new species of the genus Cirrhimuraena (Anguilliformes: Ophichthidae) from the Bay of Bengal, India.

A new species of the genus Cirrhimuraena (Anguilliformes: Ophichthidae), Cirrhimuraena indica sp. nov., is described based on eight specimens collected from the Paradip (Odisha) and Petuaghat harbours (West Bengal) along the Bay of Bengal. The species is distinct in having the upper jaw fringed with 16-17 cirri before posterior nostril and 4-5 in between the anterior and posterior nostrils on the side; dorsal fin originates above the level of gill opening, predorsal length is 9.3-10.9 in total length; the head is relatively large, the length is 9.3-9.8 in total length; no infraorbital pores are observed between the nostrils; teeth are numerous, small, conical and in bands on each jaw; pores are present before the gill opening 10-11 and before anus 47-48; pectoral-fin length is 2.4-2.8 in head length; predorsal vertebrae are 8-10, pre-anal vertebrae 43-47 and total vertebrae 164-169. In the maximum likelihood tree analysis for COI gene, the new species belongs to the same clade as the other congener of Cirrhimuraena chinensis and is separated from the species morphologically and genetically.

A new deep-water species of snake eel, Xyrias anjaalai sp. nov. (Anguilliformes: Ophichthidae), from the Western Indian Ocean.

A new species of snake eel Xyrias anjaalai sp. nov. (Anguilliformes: Ophichthidae) is described from morphological analysis of 12 specimens and molecular analysis of four specimens, caught off Kollam, Kerala, southwestern India, by deep-sea trawling. X. anjaalai is distinguished from its congeners by having a large eye diameter, a short snout, a different dentition pattern as in the 3rd row of maxillary teeth beginning at the level of the 4th vomerine tooth between the two existing rows in the inner series of maxillary teeth, an irregular tooth patch for approximately 1/10th of the lateral side of the dental arch in the distal portion and a vertebral count of predorsal vertebrae 18-21, preanal vertebrae 73-76 and total vertebrae 147-149. Phylogenetic relationships of X. anjaalai with other species in Ophichthidae were examined using partial nucleotide sequences of the COI gene (617 bp). The genetic analyses suggest that the new species is closest to X. revulsus followed by Apterichtus klazingai with Kimura 2 parameter (K2P) values of 0.6 and 2.8% respectively. In the phylogenetic reconstruction, sequences of X. anjaalai formed a distinct clade demonstrating their uniqueness as a separate species.

New Geographical Record for Muraenid Eels (Anguilliformes: Muraenidae) along the Northeast Arabian Sea, Western Indian Ocean

Fishes of family Muraenidae, popularly known as moray eels, are one of the most diverse groups among true eels. Gymnothorax is the most predominant genus in terms of diversity along Indian coastline (31 species including recent description and distributional records), but they rarely form the fishery of commercial importance. Gymnothorax dorsalis, species of elongated unpatterned moray eels characterized by eight to nine pre-dorsal vertebrae, three infraorbital pores and low dorsal and anal fin united with caudal fins is reported for the first time from the west coast of India. Gymnothorax reticularis, reticulated patterned eel with 18–19 vertical dark bars, five pre-dorsal vertebrae and 10–11 vomerine teeth is also reported for the first time from the northwest coast of India.

Ophichthus kailashchandrai sp. nov. (Anguilliformes: Ophichthidae): a new species of snake eel from Indian waters, Bay of Bengal.

A new snake eel (Anguilliformes: Ophichthidae: Ophichthinae) species, Ophichthus kailashchandrai sp. nov., is described from three specimens, collected from the Shankarpur fishing harbour located on the northern part of the Bay of Bengal, West Bengal, India. Ophichthus kailashchandrai sp. nov. is distinguished from its congeners by having its dorsal-fin origin at the posterior third of the pectoral fin, preanal length 2.6-2.8 in TL, uniserial maxillary and mandibular teeth and vertebral count (predorsal vertebrae 14-15, preanal vertebrae 54-55, and total vertebrae 180-182).

Two new species of the genus Ophichthus from the western central Pacific Ocean, with a redescription of Ophichthus megalops Asano, 1987 (Anguilliformes: Ophichthidae).

Two new species similar to Ophichthus megalops Asano, 1987 with dark-tipped anal fins, are described on the basis of one specimen of each species. Ophichthus semilunatus sp. nov. from northeastern Taiwan is characterized by having 176 total vertebrae, three rows of teeth on the maxilla, one + three supraorbital pores, two preopercular pores, a brownish anterior-nostril tube, and a blotch on the anterior margin of anus. Ophichthus brevidorsalis sp. nov. from New Caledonia is characterized by having two preopercular pores, one + three supraorbital pores, smaller eyes 2.7 in head, a short head 9.5% of total length, a long tail 59.8% of total length, a slightly short snout 19.4% of head, and 43 predorsal vertebrae. A redescription of O. megalops is provided based on the holotype and 18 specimens newly collected from Taiwan. Selected characters of all nine Ophichthus with a dark-tipped anal fin are provided. In addition, partial COI sequences of five species is provided.

A new short brown unpatterned moray eel Gymnothorax andamanensis (Muraenidae: Muraeninae) from Andaman waters, India.

Gymnothorax andamanensis sp. nov., a new short brown moray eel, is described here on the basis of two specimens collected from Port Mout, Port Blair, South Andaman (11.659327°N; 92.696148°E), caught using baited hand-lines in a sandy habitat at a depth of less than 2 m. The species is characterized in having the dorsal-fin origin before the gill opening, pre-anal length 2.1-2.2, jaw pores with black rim, two branchial pores, predorsal vertebrae 3, preanal vertebrae 57 and total vertebrae 135-136, teeth smooth, three large fang-like median intermaxillary teeth, biserial maxillary and uniserial vomerine teeth, and dentary teeth biserial with two teeth in each side in the second row of the dentary. The new species is compared with all 10 short brown unpatterned moray eels known from the world and two from Indian waters.

New Record of Alburnoides kosswigi (Pisces: Leuciscidae) in the Ilgın Lake Basin

Alburnoides kosswigi was described from the Sakarya River. Morphological data reveal that it also inhabits in the stream Beykonak, a tributary of the Ilgın Lake in Central Anatolia. The Ilgın population of Alburnoides kosswigi has distinguished features such as a scaleless keel between the posterior pelvic-fin base and the anus, the eye diameter approximately equal to the snout length and the interorbital distance, 42–47 total lateral-line scales, 11½–13½ branched anal-fin rays, 38–39 total vertebrae, 11-12 predorsal vertebrae, and 7–8 gill rakers.

DNA barcoding adjudicate two different morphs of Bascanichthys deraniyagalai (Anguilliformes: Ophichthidae): re-description and first record from Chilika lagoon, India

Morphological characters and distribution pattern of the snake eel, Bascanichthys deraniyagalai is debatable during the past half-century. Thus, the species is re-described herewith by morphometry, vertebrae, and molecular data. In recent Chilika expedition in India, we have collected 10 specimens and observed a vertebral count dimorphism. The present study distinctly detected two vertebral groups of B. deraniyagalai: first group with 5 predorsal vertebrae, 81–83 preanal vertebrae, 190–196 total vertebrae in females; however, the sex of the second group with 5 predorsal vertebrae, 72–74 preanal vertebrae, 176–178 total vertebrae was not able to confirm. Further, the molecular data of morphologically identified two distinct groups of B. deraniyagalai shows negligible Kimura 2 parameter genetic divergence and cohesive clustering in Neighbor-Joining phylogeny proved to be the two different morphs of the same species. Hence, the present study indicated there might be vertebral count or sexual dimorphism in B. deraniyagalai, which need further sampling and taxonomic revision to unwrap the fact.

A new Miocene skate from the Central Paratethys (Upper Austria): the first unambiguous skeletal record for the Rajiformes (Chondrichthyes: Batomorphii)

A new fossil skate, Ostarriraja parva gen. et sp. nov., represented by a single partial articulated skeleton collected from the early Miocene fish-bearing strata of Upper Austria, is described here in detail. This taxon exhibits a unique combination of skeletal and dental features (e.g. nasal capsules broad and oval; presence of pectoral arch; compound radial articulated with single radial segments in serial fashion; separated pelvic girdle condyles; reduced catenated calcification of radials; about 86 pectoral radials; 20–21 pelvic-fin radials; 65–70 predorsal vertebrae) that clearly support its assignment to a new genus of the order Rajiformes, and the phylogenetic analyses reveal its basal position within the group. The comparison between Ostarriraja and the holomorphic batoids from Late Cretaceous of Lebanon traditionally aligned with skates concurs to suggest that this Neogene occurrence represents unquestionably the first known skeletal record for the group. The morphological and phylogenetic affinities of Ostarriraja with the living skates suggest a close association of this taxon with the temperate-cold water environments hypothesized for the Central Paratethys during the early Miocene.http://zoobank.org/urn:lsid:zoobank.org:pub:8BB8F0F3-35C5-47FA-AE3C-2CBF445C4BCA

Eels of the genus Bathyuroconger in the northwestern Pacific, with descriptions of four new species (Anguilliformes: Congridae).

Examination of the congrid genus Bathyuroconger in the northwestern Pacific reveals six species are present. Bathyuroconger albus sp. nov. differs from congeners in having a pale coloration, a moderately reduced gill opening that is close to but not touching the pectoral-fin base, trunk length 2.0-2.9 times HL, preanal vertebrae 45-54, preanal lateral-line pores 42-48. Bathyuroconger dolichosomus sp. nov. has a moderately reduced gill opening that is close to but not touching the pectoral-fin base, trunk length 3.2 times HL, preanal vertebrae 63, and preanal lateral-line pores 61. Bathyuroconger fowleri sp. nov. has a small gill opening distant from the pectoral-fin base, trunk length 1.7-2.1 times head length, dorsal-fin origin over middle of pectoral fin, predorsal vertebrae 10-14, preanal vertebrae 48-52, total vertebrae 173-178. Bathyuroconger hawaiiensis sp. nov. has a slightly reduced gill opening, separated from the pectoral-fin base, dark color, total vertebrae 201-210. Bathyuroconger parvibranchialis (Fowler, 1934), redescribed herein, has a small gill opening distant from the pectoral-fin base, dorsal-fin origin over base of pectoral fin, trunk length 1.4-1.7 times in HL, preanal vertebrae 43-48, total vertebrae 181-189, and a uniformly dark color in adults. Bathyuroconger cf. vicinus has a full-size gill opening in contact with pectoral-fin base, dark color, and total vertebrae 196-201. A key to the species in the northwestern Pacific is provided.

A new species of the genus Dysommina (Teleostei: Anguilliformes: Synaphobranchidae: Ilyophinae) from the Western Pacific.

Dysommina orientalis, a new species of Ilyophine eel from off Taiwan and Japan is described and illustrated. The species had long been recognized as Dysommina rugosa in the western Pacific and is distinguished from D. rugosa by a lower number of predorsal vertebrae, a higher number of total vertebrae, shorter head length, smaller eye size, reduced vomerine dentition, and an increased number of both mandibular and maxillary teeth, as well as significant differences in DNA sequence in COI and 16S.

First Report of Genus Diploconger (Congridae: Congrinae) from the Indian Coast

Present study reports a moderately elongate, light brown coloured eel, Diploconger polystigmatus Kotthaus, 1968, for the first time from Indian waters. The species is differentiated from other congridae in having the following combination of characters: double row of cephalic and lateral-line pores, dark brown strip from the middle of the supratemporal commissure up to the tip of the mouth, dorsal fin origin nearly from the halfway of pectoral fin, each dorsal fin ray have black spots at the base, pre-dorsal vertebrae 9, pre-anal vertebrae 27, total vertebrae 108. The present report also reports the genus Diploconger for the first time from Indian waters.

Gymnothorax odishi sp. nov. (Muraenidae: Muraeninae), a short brown unpatterned moray eel from Bay of Bengal, India.

Gymnothorax odishi sp. nov., a new short brown moray eel, is described here on the basis of eleven specimens collected from Gopalpur, Odisha, along the east coast of India, Bay of Bengal. The species is characterized with dorsal-fin origin before gill opening, jaw pores with dark rim, small black patch just behind the eye of about eye size or more, gill opening with dark rim, two branchial pores, predorsal vertebrae 4, preanal vertebrae 55-58 and total vertebrae 133-138, three large fang like median intermaxillary teeth, uniserial maxillary and vomerine teeth. The new species is compared with all short brown unpatterned moray eels known from the world.