Lateral Line Scales Research Articles

Revalidation of Enteromius alberti and presence of Enteromius cf. mimus (Cypriniformes: Cyprinidae) in the Lake Edward system, East Africa

A revision was done on the species of Enteromius Cope, 1867 (Cypriniformes: Cyprinidae) from the Lake Edward system with a smooth, flexible third unbranched dorsal fin ray without serrations. Specimens with these characteristics had previously been attributed to E. perince and E. stigmatopygus. A combination of a genetic (COI, mtDNA) and a morphometric approach was used. Based on the COI gene, we found two groups with a distance of 8.5%, though neither of the two corresponded to E. perince or E. stigmatopygus. One group revealed to be conspecific with E. alberti, previously a synonym of E. stigmatopygus, described from the Rutshuru River, May-Ya-Moto (DRC, Lake Edward system), and revalidated here. In addition, E. cercops, described from the Nzoia River (Kenya, Lake Victoria basin), is put in synonymy with E. alberti. The second group was most similar to E. mimus, but differed morphologically somewhat from the types of E. mimus. Therefore, specimens of this group were identified as E. cf. mimus. Morphologically, E. alberti can be separated from E. cf. mimus based on a higher number of lateral line scales and smaller values for interorbital width, pre-pelvic distance, body depth, maximum and minimum caudal peduncle depth, head width and head depth.

Review of the genus Malacoctenus (Actinopterygii: Labrisomidae) from the Southwestern Atlantic, with description of two new species

The labrisomid genus Malacoctenus from Southwestern Atlantic is reviewed. Two new species of scaly blennies formerly reported by several authors as Malacoctenus triangulatus are described. One is found at the oceanic islands Fernando de Noronha Archipelago and Atol das Rocas, and the other is distributed along the Brazilian coastline. The two new species differ from other species of the genus and from each other by different combinations of the number of lateral-line scales, number and size of head cirri, and color pattern. Molecular data also support species' distinctiveness between M. triangulatus and the species described herein. Two additional recognized Brazilian species, M. delalandii and M. brunoi are described and illustrated and an identification key to all recognized Atlantic species is provided.

Discovery of A New Teleost Fish, Puntius ocellus from Kerala, India

A new Puntius species is described from a freshwater stream of Kerala, India. It is related to Puntius mahecola, P. amphibius, P. euspilurus, and P. kyphus; all these are small elongate fishes with laterally compressed body having a non-ossified and weak last simple dorsal fin ray. But the new fish shows a number of differences from its close relative species. It can be distinguished from its congeners in having a pointed and unusually elongated snout, a weak and non-osseous last simple dorsal fin ray, 23-24 lateral line scales, 2 ½ scales between lateral line and ventral fin, 7-8 predorsal scales, and a distinct golden or yellow ring surrounding its large caudal black spot on posterior most lateral line scales. The new fish is not uncommon in the water bodies of Kazargod; it is edible and can be used as ornamental fish. The new species is taxonomically analyzed and compared with its congeners.

A New Species of Hypomasticus from Eastern Brazil Based on Morphological and Molecular Data (Characiformes, Anostomidae)

A new species of Hypomasticus is described from the Rio de Contas, a coastal drainage of eastern Brazil, and its phylogenetic position is proposed based on molecular data. The new species is diagnosed among Anostomidae by possessing a downturned mouth with compressed teeth arranged side by side, 37 or 38 lateral-line scales, three scale series between the dorsal-fin origin and the lateral line and between the lateral line and the pelvic-fin origin, and 12 scale rows around the caudal peduncle. Mitochondrial DNA sequences provide evidence that the new species is closely related to H. mormyrops, H. thayeri, H. copelandii, and H. steindachneri, a clade of species endemic to coastal drainages of eastern Brazil. These results combined with a previous phylogeny support the reallocation of the latter two species from Leporinus to Hypomasticus . The new species is herein considered to be Endangered under the IUCN criteria, due to a small Extent of Occurrence, severely fragmented population, and continued decline of area, extent, and quality of habitat.

Taxonomy and systematics of the 'Maharaja Barbs' (Teleostei: Cyprinidae), with the description of a new genus and species from the Western Ghats, India.

Maharaja Barbs (Teleostei: Cyprinidae), endemic to the high-altitude streams of the northern Western Ghats are currently represented by a single species, Puntius sahyadriensis. Integrative taxonomic analysis of these fishes reveals them to form a distinct clade within the Cyprinidae, for which we propose the name Waikhomia gen. nov. Waikhomia differs from Puntius and other closely related genera by a combination of characters including: barbels absent; last unbranched dorsal-fin ray smooth, with highly segmented apex; total vertebrae 30 (17 abdominal and 13 caudal); post-epiphysial fontanelle absent, frontals elongated, parietals narrow; infraorbital 2-4 large, deep and wide, overlapping cheek and preopercle; opercle not overlapping the interopercle laterally; free uroneural 2 absent; lateral line complete, with 23-25 perforated scales; pelvic fins jet black with tip of fins white; and body coloration consisting of multiple (6-8) spots and blotches on side of body. We also describe a new species of Waikhomia from the west-flowing Kali river system in the northern part of the Western Ghats, India. The new species, Waikhomia hira is distinguished from W. sahyadriensis by a combination of characters including a distinct body coloration, consisting of 7-8 small, rhomboidal spots arranged across the lateral-line scale row; 23--25 perforated lateral line scales; 10 pre-dorsal scales and 2-3 sparsely spaced gill rakers on epibranchial 1. Further, W. hira differs from its sister taxon, W. sahyadriensis, by a raw genetic distance ranging from 4.3-4.9% in partial cytochrome oxidase subunit 1, and 7.0-8.2% in partial cytochrome b genes.

Inter-population variability in morphology and reproduction of Alburnus alburnus (Linnaeus, 1758) from Bosnia and Herzegovina

Inter-population variability in morphological traits and fecundity of Alburnus alburnus (Linnaeus, 1758) from Bosnia and Herzegovina was analysed in this study. The results of the analyses based on 21 standard measurements and six meristic characters have shown the highest variation between distance between pelvic (ventral) fins and anal aperture. Analysis of variance (ANOVA) indicate statistically significant differences between six populations. Differences among meristic characters have been tested by Multiple Comparisons Kruskal-Wallas. Obtained results indicate statistically significant difference among samples for number of branched rays for caudal fin (KA/Ca), lateral line scales (Le) and a number of gill rackers (Rac). Discriminant function analysis indicate characters that had the strongest effect on the geographical variation between A. alburnus samples from Bosnia and Herzegovina. Characters with the strongest discriminant power are: preanal distance, length of pectoral fin, length of the ventral (pelvic) fin, minimum body height, caudal fins branched rays, and pelvic fins branched rays.Values for weight of the gonads and gonadosomatic index (GSI) have not shown any statistically significant difference among observed bleak populations. Regression analysis has been used to estimate the relations between GSI and standard length, body, and gonads weight. The gonadosomatic index has shown positive, non substational, relationship to gonads weight.

Systematic reappraisal of the anti-equatorial fish genus Microcanthus Swainson (Teleostei: Microcanthidae), with redescription and resurrection of Microcanthus joyceae Whitley.

The taxonomy and classification of the microcanthid fish genus Microcanthus Swainson has been a subject of contention dating back to the 19th century. Its allopatric, disjunct anti-equatorial distribution across the Indo-West Pacific has resulted in the recognition of several nominal taxa, though these have been widely regarded as synonyms of Microcanthus strigatus (Cuvier). Following the results published in a companion study elsewhere by the authors, the taxonomy of Microcanthus and the validity of these nominal synonyms are herewith revised. Microcanthus strigatus is redescribed on the basis of 66 specimens from East Asia, Hawaii and Western Australia, and M. joyceae is resurrected and redescribed on the basis of 25 specimens from eastern Australia and the southwest Pacific. Microcanthus differs from other microcanthid genera in having the following combination of characters: dorsal-fin rays XI,15-17 (usually XI,16); anal-fin rays III,13-15 (usually III,14); pectoral-fin rays 15-17 (usually 16); scales ctenoid with ctenial bases present; lateral-line scales partially or heavily obscured by adjacent scales; and body pale in preservation with five horizontal dark stripes reaching the posterior edges of dorsal and anal fins, and base of caudal fin. The review is accompanied by a key to the genera of Microcanthidae.

New Distributional Record of Oblique-barred Monocle Bream Scolopsis xenochrous, Günther, 1872 (Perciformes: Nemipteridae) from Wadge Bank of Southeastern Arabian Sea

The present study reports the Scolopsis xenochrous Gunther, 1872 off Vizhinjam coast, from Wadge Bank, Southeastern Arabian Sea. Four specimens of S. xenochrous were collected at a depth of 20 to 30 m by a gill net operated by traditional fishing craft. The morphometric and molecular identification characters of the verified specimens are described. The most of the morphometric measurement and meristic counts were confirmed with earlier explanation of S. xenochrous: Totally 45–46 lateral line scale, caudal fin deeply forked and upper lobe slightly lengthier than the lower lob and produced into a short or moderately long filament. Further, it has six oblique rows with thirty-two numbers of brown spots and an elongate white to bluish blotch below the lateral line. The present Indian specimen’s sequences were compared with other sequences of the S. xenochrous and other species of this genus obtained from the NCBI, BOLD, and Cryobank. The overall level of intra-species genetic distances was 2.7%, between Taiwan, Indonesia and Philippines were showed 0.0-0.5% of variation except for KY362992. The present study revealed the first record for the Wadge Bank coast of Southeastern Arabian Sea.

A New Species of Chromis (Teleostei: Pomacentridae) from Mesophotic Coral Ecosystems of Rapa Nui (Easter Island) and Salas y Gómez, Chile

A new species of Chromis (Teleostei: Pomacentridae) is described from three specimens collected at 90 m depth in a mesophotic coral ecosystem at Rapa Nui, Chile. Chromis mamatapara, new species, can be distinguished from its congeners by the following combination of characters: dorsal-fin rays XIV,13–14; pectoral-fin rays 18–19, third from top of fin longest; tubed lateral-line scales 18; total gill rakers on first arch 30–32; vertebrae 11+15; and by coloration of living specimens, especially the presence of a single, pronounced, white spot, roughly the same diameter as the orbit, located where the posterior base of the dorsal fin intersects the caudal peduncle. The most similar DNA barcode (mitochondrial COI gene), among those available, is Chromis tingting from Japan (3.5% uncorrected divergence); however, C. mamatapara, new species, also superficially resembles other species for which sequences are unavailable for comparisons, including C. okamurai from Japan and C. struhsakeri from Hawaii. Due to the high geographic isolation and consequently high endemism in the Rapa Nui region, we believe that C. mamatapara, new species, is endemic to mesophotic ecosystems of Rapa Nui, Isla Salas y Gomez, and nearby seamounts, a discovery that contributes to the high endemism of the region and thus the need for conservation efforts.

NEW DISTRIBUTIONAL RECORD OF THE BEARDLESS BARB Cyclocheilichthys apogon (VALENCIENNES, 1842) (CYPRINIFORMES: CYPRINIDAE) FROM MADURA ISLAND, INDONESIA

Beardless Barb Cyclocheilichthys apogon (Valenciennes, 1842) is a species known from Southeast Asia, including Western Indonesia area (Borneo, Sumatra and Java). In Java Island, it was previously found in the mainland area. This paper provides the first record of C. apogon in the Lembung River, one of the major rivers in Madura Island, thereby extending the species distribution up to 150 km northeast from the earlier record. The specimens of C. apogon were characterized as follows: dorsal fin rays 12; anal fin rays 8–9; pectoral fin rays 17–18; lateral line scales 34–35. A description of detailed morfological characters of a specimen are provided.

Sarcocheilichthys vittatus, a new species of gudgeon (Teleostei: Cyprinidae) from the Poyang lake basin in Jiangxi Province, South China.

Sarcocheilichthys vittatus, a new species of gudgeon, is described from the Gan-Jiang and Fu-He flowing into the Poyang Lake Basin in Jiangxi Province, South China. It is similar to S. parvus and S. caobangensis in having a longitudinal black band extending from the snout tip to the caudal-fin base, a character separating them from all other congeneric species, but distinct from S. parvus in having more lateral-line scales, no longitudinal yellowish stripe above the lateral black band on the flank and no barbels, and from S. caobangensis in possessing two shorter lateral lobes of the lower lip restricted only to the side of the lower jaw, no black spots along the dorsal-fin base and a stouter caudal peduncle. Its validity was also warranted by a molecular phylogenetic analysis based on the cyt b gene. Critical notes were provided on some currently recognized Chinese congeners.

Characidium chancoense, a new species of South American darter from the Río Cauca drainage, Colombia (Characiformes: Crenuchidae)

Characidium chancoense new species, is described from the transandean upper Río Cauca drainage in Colombia. It can be distinguished from all congeners by its pigmentation pattern that consists of 7-12 vertical bars, most of which are cuneate-shaped with the vertex ending on or just below the lateral-line scale series, except for the last 1-4, which are dorsoventrally elongate rectangular bars that extend well below the lateral line. Characidium chancoense is sympatric with C. caucanum Eigenmann, C. phoxocephalum Eigenmann, C. cf. zebra Eigenmann and C. cf. boavistae Steindachner. Unlike C. caucanum and C. cf. boavistae, C. chancoense does not appear to be sexually dimorphic.

Three new species of the barracudina genus Lestidium (Aulopiformes: Paralepididae) from the Indo-West Pacific.

Three new species of the genus Lestidium with complete lateral line are described from the Indo-west Pacific Ocean. Lestidium longilucifer sp. nov., from Western Australia and Taiwan, belongs to the Lestidium atlanticum species complex and can be separated from other congeners by having 41-43 prehaemal vertebrae, 85-88 total vertebrae and 126-146 total lateral-line scales; and body proportions. Lestidium australis sp. nov. from eastern Australia and Lestidium rofeni sp. nov. from Taiwan and the Philippines together with Lestidium prolixum form the L. prolixum species complex. These three species can be separated from each other by a combination of different fin positions, vertebral formula, number of lateral-line scales and pigmentation.

Spirlins of the southern Black Sea basin, with the description of a new species(Teleostei: Leuciscidae).

Alburnoides turani, new species, from the Filyos River drainage is described and the distribution of the nine other Alburnoides species known from the southern Black Sea basin is revised. Alburnoides turani is distinguished by having a naked ventral keel, or the keel is covered with 1-3 scales between the posterior pelvic-fin base and the anus, an interorbital distance wider than the eye diameter and the snout length, 48-55 total lateral-line scales, 5-6 scale rows between the anal-fin origin and the lateral line, 13½-14½ branched anal-fin rays, and 41-42 total vertebrae.

Parapsilorhynchus alluriensis, a new species of cyprinid fish (Teleostei: Cyprinidae) from the Eastern Ghats, of India.

A new species of cyprinid fish, Parapsilorhynchus alluriensis, is described from the Alluri Hills of Andhra Pradesh State, India. It is distinguished from its congeners by the combination of the following characters: A poorly-developed callous pad present behind lower lip; head deep (depth at occiput 47.3-72.3% head length, HL); body stout and deep (depth at dorsal fin origin 17.3-21.7 % standard length, SL); gape width 27.3-32.8% HL; inter-orbital space 33.9-43.2% HL; lower lip rounded; mouth opening situated very close to the anterior tip of snout; upper lip concealed by a poorly-developed rostral fold which is slightly fringed; minute papillae on rostral fold; 3 simple pectoral-fin rays; 33-34 lateral-line scales. A partial phylogeny based on the DNA Barcode COI gene suggests a sister-group relationship between the new species and P. prateri. Till date, the genus consists of four species from the Western Ghats, three from the Eastern Ghats, including the species described herein totaling it to seven from the peninsular India.

A new species of Hemiodus Müller (Characiformes: Hemiodontidae) from the lower Rio Xingu, Brazil.

A new species of Hemiodus is described from the Rio Xingu basin, Pará, Brazil. It is distinguished from congeners by the combination of presence of a dark longitudinal stripe extending from head to tip of lower caudal-fin lobe, an oblique blotch on dorsal-fin, 9-11 scale rows above lateral line, 58-66 perforated lateral line scales, and 17-20 circumpeduncular scales. Comments on the conservation status of the new species, as well as its relationships among Hemiodus species, are made.

A new endangered species of Megaleporinus (Characiformes: Anostomidae) from the Rio de Contas basin, eastern Brazil.

A new species of Megaleporinus is described from the Rio de Contas, a coastal drainage of eastern Brazil, and its phylogenetic relationships are studied using molecular data. The new species is unique among Anostomidae by possessing two exclusive features: an irregular dark longitudinal stripe from supracleithrum to second midlateral blotch and anterior cranial fontanel partially closed. In addition, the new species is diagnosed by having three premaxillary teeth, three dentary teeth, 37 or 38 scales in lateral line, 16 scale rows around caudal peduncle, three dark midlateral blotches on body, and red fins in life. The new species is closely related to M. obtusidens from the São Francisco basin, corroborating previous studies that indicated that the latter represents a species complex as currently defined. The new species exhibits the first rib enlarged in mature males, a feature described for some congeners. The new species is herein considered to be Endangered under the IUCN criteria.

Barbus xanthos, a new barbel from the Southern Aegean basin (Teleostei: Cyprinidae).

Barbus xanthos, a new species, is described from the Eşen, Dalaman, Tersakan and Büyük Menderes rivers in south-western Anatolia. It differs from other Barbus species in the adjacent basins by having 53-60 lateral line scales, a weakly ossified last unbranched dorsal-fin ray (about 33-50%), numerous small irregular-shaped black or dark-brown spots smaller than scales, often forming large, black or dark-brown blotches on back and flank in juveniles and adults, and a straight or slightly convex posterior dorsal-fin margin. B. xanthos differs from its most closely related congener, B. pergamonensis, by nine nucleotide substitution sites in the mitochondrial DNA cytochrome oxidase I barcode region.

Unexpected species diversity within Sri Lanka’s snakehead fishes of the Channa marulius group (Teleostei: Channidae)

The taxonomic status of the large snakeheads of the Channa marulius group that occur in Sri Lanka is reviewed and clarified. Two species are recognized from the island, based on both morphological and molecular (cytochrome c oxidase subunit 1: cox1) differentiation: C. marulius Hamilton from the northern dry zone and C. ara Deraniyagala from the middle and lower regions of the Mahaweli basin. Channa ara is endemic to Sri Lanka and can be distinguished from its Marulius group congeners, C. marulius, C. aurolineata and C. auroflammea, by having fewer dorsal- and anal-fin rays, fewer lateral-line scales and fewer vertebrae; from C. marulioides by a different adult colour pattern; and from C. pseudomarulius by having more vertebrae. At the cox1 barcoding locus, Channa ara is at least 3.6% genetically different from C. marulius, and at least 8% different from the other described species in the group. Specimens collected from the southwestern wet zone in Sri Lanka are a puzzling third component of the Marulius group's diversity, uncovered in this study, and identified here as C. cf. ara. Whilst genetically more similar to C. marulius, C. cf. ara possesses fewer dorsal- and anal-fin rays, fewer lateral-line scales and fewer vertebrae and is therefore morphologically more similar to C. ara. Channa ara can be distinguished from C. cf. ara, however, by differences in circumpeduncular scale count, adult colour pattern, and by an uncorrected pairwise genetic distance of 3.7% in cox1 sequences. A neotype is designated for Ophicephalus marulius ara Deraniyagala.

Body shape variation of Garra rufa (Heckel) (Teleostei: Cyprinidae) using geometric and morphometric techniques

Organisms can adapt to habitat conditions that ensure their survival. Habitat separation can lead to different populations of body shape during the phenotypic plasticity process. Both traditional and modern (geometric) morphology are being used in fish population studies. In this study, the body shape differences between Garra rufa (Heckel) populations captured in the Jarrahi River (from the Tigris Basin) were investigated using traditional and geometric morphometric methods. The samples were captured from the Rostam Abad, Aghajari and Behbahan tributaries and transferred to the laboratory. For the traditional morphometric analysis, 10 meristic characters and 19 morphometric characters were measured. Geometric morphological information was extracted using 13 landmark points on left side photographs of individual fish. According to the results of the traditional morphometric analysis, there were differences between the three populations in meristic (lateral line scales, predorsal scales, circamucaudal scales) and morphometric (14 of 19 characters) traits. In the geometric morphometric analysis, the major part of the shape variation is due to landmark points in the head region and the dorsal fin base, with the anal fin and caudal peduncle being the most conservative body regions. The populations had significant differences in body shape with populations from Aghajari and Behbahan tributaries being most similar and the Rostam Abad population was different from the two other populations.