Number Of Lateral Line Scales Research Articles

Patterns of Phenetic Diversity and Taxonomy of the Ide <i>Leuciscus idus</i> (Cypriniformes, Cyprinidae) from Water Bodies of Russia and Adjacent Countries

Using the methods of population morphology, we studied the structure of phenetic diversity of the ide Leuciscus idus (L.) from the water bodies of the Russian Federation and some neighboring countries. We analysed our own collection and literature data on meristic characters of external morphology, axial skeleton, as well as the pharyngeal teeth formula. The main features contributing to population differentiation were the number of lateral line scales, total vertebrae count, caudal and pre-caudal vertebrae ratio. It was shown that the strong positive relationships of the first two features with the geographical latitude of fish habitats is associated, first of all, not with the direct influence of physical factors functionally dependent on latitude, but with particular (sub)speciation processes in river basins and dispersal of evolutionarily derived forms to the north. The results obtained are discussed in terms of evolutionary trends in the subfamily Leuciscinae and call for a taxonomic revision of the L. idus species in its current volume with elevation of the former subspecies L. idus oxianus to a species rank.

Revision of Nannocharax luapulae Boulenger,1915 (Characiformes: Distichodontidae) from the Upper Congo basin: Evidence for a species pair.

For many decades, Nannocharax luapulae has been considered to be widespread in the southern part of the Upper Congo basin. However, meristic, morphometric and cytochrome c oxidase subunit I (COI) barcoding evidence revealed that its geographical distribution is restricted to the Luapula-Moero basin. The populations of the Upper Lualaba are assigned to a new species, N. chochamandai. This new species, though highly similar to N. luapulae, can readily be distinguished from it by its lower number of lateral line scales, 41-46 (vs. 49-55), its pectoral fin reaching the pelvic-fin insertion (vs. not reaching the pelvic-fin insertion) and its pelvic fin reaching the base of the anal fin (vs. not reaching the base of the anal fin). Specimens of N. chochamandai display thickened pads on the first three pelvic-fin rays that exhibit intraspecific variation in development, which appears to be related to the flow-strength of the river in which these Nannocharax specimens occur. Nannocharax luapulae is redescribed and an updated identification key to the Nannocharax species of the Congo basin sensu lato is provided as well. Some fish conservation issues related to N. luapulae and N. chochamandai are also highlighted.

A new cyprinid from the Oligocene of Qaidam Basin, north-eastern Tibetan plateau, and its implications

The Qaidam Basin, lying in the north-eastern Tibetan Plateau, China, is key to understanding the Cenozoic climatic and biological changes that have occurred on the plateau; however, information from a palaeontological perspective on this Palaeogene basin is scant. Recently, fossil cyprinids were found in the middle portion of the Shangganchaigou Formation (= Upper Ganchaigou Formation; Oligocene) in the north-western Qaidam Basin. These share many osteological characters with barbines and ‘morphologically primitive clade schizothoracines’ (= primitive schizothoracines; i.e. Schizothorax and Aspiorhynchus), and they closely resemble the latter in the size and shape of the scales: body scales are small and oval; the number of lateral line scales exceeds 100; and the long-oval scales from the pre-anal region are very similar to the ‘anal scales’, which are unique to schizothoracines. Compared with another fossil fish, Paleoschizothorax qaidamensis, from the same formation, the major differences are: (1) the posterior part of the entopterygoid in the new material is normal and not expanded while that of P. qaidamensis is obviously expanded; and (2) the premaxilla process of maxilla is well developed in P. qaidamensis but weak in the new specimens. Therefore, they are described as a new species of the fossil genus Paleoschizothorax (subfamily Schizothoracinae): Paleoschizothorax diluculum sp. nov. A phylogenetic analysis, which included 13 extant genera and three fossil forms of barbines and schizothoracines and 70 morphological characters, also supports the close relationship between P. diluculum and primitive schizothoracines. A preliminary correlation analysis suggests that the degree of reduction of body scale size is negatively correlated with habitat mean temperatures among most Chinese cyprinids. Moreover, we speculate that the ‘primitive schizothoracines’ likely originated in the north-eastern–central Tibetan Plateau based on the fossil records and molecular phylogeny of the extant taxa. http://zoobank.org/urn:lsid:zoobank.org:pub:C461C7C0-9BAB-44DD-8DEE-0B5BB03D6479

A New Species of Bridled Darter Endemic to the Etowah River System in Georgia (Percidae: Etheostomatinae: Percina)

Percina freemanorum, the Etowah Bridled Darter, is described as a new species endemic to the Etowah River system in Georgia, specifically in Long Swamp Creek, Amicalola Creek, and the upper portion of the Etowah River. The earliest collection records for Percina freemanorum date to 1948 and in 2007 the species was delimited as populations of Percina kusha. Our investigation into the systematics of Percina kusha is motivated by the uncertain status of populations in the Coosawattee River system and observed morphological disparity in several meristic traits between populations in the Conasauga and Etowah River systems. Our analyses of morphological divergence, nuclear genotypes, and mitochondrial DNA (mtDNA) haplotype networks confirm the distinctiveness of Percina freemanorum. Morphologically, Percina freemanorum is distinguished from Percina kusha through lower average numbers of lateral line scales (65.4 vs. 72.3); rows of transverse scales (18.0 vs. 21.4); scales around the caudal peduncle (22.1 vs. 24.9); and modally more pectoral fin rays (14 vs. 13). The two species are not reciprocally monophyletic in phylogenetic analysis of mtDNA sequences, but the two species do not share mtDNA haplotypes. Analysis of up to 158,000 double digest restriction-site associated DNA (ddRAD) sequencing loci resolve each of the two species as reciprocally monophyletic and genomic clustering analysis of single nucleotide polymorphisms identifies two genetic clusters that correspond to the morphologically delimited Percina freemanorum and Percina kusha.

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.

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.

Hidden species diversity in Marcusenius moorii (Teleostei: Mormyridae) from the Congo Basin.

New collections from the Yangambi Biosphere Reserve (YBR) and Okapi Wildlife Reserve (OWR) revealed the presence of two groups of specimens similar to, but different from Marcusenius moorii. To study both these groups, an integrated morphological and genetic (mtDNA, cytb) approach was used. This study revealed that one of the two groups is conspecific with Marcusenius lambouri, a junior synonym of M. moorii, which is herein revalidated, with M. moorii longulus as its junior synonym. Marcusenius lambouri differs from M. moorii by a higher number of lateral line scales (44-46 vs. 40-43), a shorter pectoral-fin length (14.6-19.9 vs. 20.3-25.2% standard length; LS ) and a more elongated body due to a usually shallower middle body depth (19.8-26.5 vs. 26.3-35.9% LS ). The other group revealed to be a new species for science, Marcusenius verheyenorum, which can be distinguished from its congeners with eight circumpeduncular scales by the following unique combination of characters: a rounded head with a terminal mouth; a short and deep caudal peduncle (middle caudal-peduncle depth, 44.9-54.6% caudal-peduncle length; LCP ), a deep body (middle body depth, 27.7-34.2% LS ), 38-43 scales on the lateral line, 40-41 vertebrae, 20-21 dorsal-fin rays and 26 anal-fin rays. Some specimens previously attributed to M. moorii were examined and reassigned to M. lambouri or M. verheyenorum. As a result, M. moorii and M. lambouri occur in sympatry in the middle Congo Basin, with the distribution area of M. moorii still further extending into the lower Congo Basin. Instead, the distribution of M. verheyenorum is limited to some right bank tributaries of the upstream part of the middle Congo Basin. Two museum records from the Lilanda River (YBR), collected in the 1950s and previously identified as M. moorii, were re-identified as belonging to the new species, M. verheyenorum. However, the species now seems locally extinct in that region, which reflects the significant anthropogenic effects even within this reserve.

Liopropomaincandescens sp. nov. (Epinephelidae, Liopropominae), a new species of basslet from mesophotic coral ecosystems of Pohnpei, Micronesia.

A new species of the genus Liopropoma Gill found on the lower mesophotic coral ecosystem of Pohnpei, Micronesia, is herein described. Liopropomaincandescenssp. nov. differs from its congeners in coloration, number of lateral-line scales, number of pectoral fin rays, body depth, and snout length. Liopropomaincandescenssp. nov. is the 31st species in the genus. It was collected from a small rocky crevice in a steep slope at 130 m depth. Water temperature was 20 °C and benthic habitat was dominated by gorgonians, sponges and tunicates.

Scolopsislacrima, a new species of monocle bream (Teleostei, Perciformes, Nemipteridae) from New Caledonia.

The new monocle bream Scolopsislacrimasp. nov. is described from a single specimen (213.6 mm standard length) collected from Grande-Terre Island, New Caledonia. The new species closely resembles S.meridiana, both species having the upper part of the pectoral-fin base with reddish blotch when fresh, two bands across the top of the snout, a dorsal scaled area on the head reaching anteriorly to between the anterior margin of the eye and anterior nostril, a similar number of lateral-line scales, and absence of a small antrorse spine below the eye. However, S.lacrimasp. nov. is distinguished from S.meridiana by having diagonal lines on the body absent (vs. 18–20 diagonal lines in the latter), a dark longitudinal band below the lateral line (vs. longitudinal lines absent), the caudal fin central area not patterned (vs. with several dark horizontal lines), a narrower body and shallower caudal peduncle.

A new Chondrostoma species from the Büyük Menderes River Basin, Turkey (Teleostei: Cyprinidae)

In a study of the fishes of the Büyük Menderes River Basin, Aegean region of Turkey, two populations of Chondrostoma were found which showed clearly distinctive characters: the population from the Upper B. Menderes (Işıklı Lake) was attributed to C. meandrense Elvira, 1987, while the population from the Çine Stream in the Lower B. Menderes River basin proved to be a hitherto undescribed species: Chondrostoma turnai sp. n. Altogether 24 metric and 7 meristic parameters were compared. The new species is distinguished from C. meandrense and all other cogeners by a combination of the number of lateral line scales, the number of scale rows between the lateral line and the dorsal-fin origin, the number of scale rows of the lateral line and pelvic-fin origin, and the number of gill rakers on the first gill arch.http://www.zoobank.org/urn:lsid:zoobank.org:pub:811C213D-BEDD-4C8C-AE57-BFFA7964781A

Evaluating Morphological Asymmetry in Three Species of the Genus <i>Hydrocynus</i> from the White Nile in Sudan

The present study aimed to determine and evaluate the level of fluctuating asymmetry (FA) of morphological characters for three species of Hydrocynus from the White Nile. In H. vittatus 41% of morphological characters fluctuated to the right side and 59% to left side. In H. brevis 50% fluctuated to right and 50% to left side, while in H. forskalii 34% fluctuated to right and 66% fluctuated to left side. More scales were recorded along the lateral line on the right side of H. vittatus and H. brevis compared to H. forskalii , while more gill rakers were recorded on the left side of H. vittatus . The smallest asymmetry index was found for PVFL of the three species and the largest index was found for POL of H. brevis . Mean asymmetry index was (3.5%) in H. forskalii , (5.1%) and (4.9%) in H. vittatus and H. brevis , respectively. Absolute asymmetry values were significantly correlated with character size for the number of lateral line scales, head length, pectoral fin length and ventral fin length (P>0.05) and highly correlated for snout length and caudal peduncle length (P>0.001) in the three species. Correlations between means of bilateral characters and body size were significant (P>0.05) for the head length, pelvic fin length and pectoral spine length of the three species. This study is the first of its kind in species of the Nile fish. The present result can be a base line for further study of fluctuating asymmetry in fish and as indicators to detect the level of pollutants in the Nile and the condition of the environment and the organisms.

Description of two deep-water fishes of the genusDiplotaxodon(Teleostei: Cichlidae) from Lake Malaŵi, Africa

Abstract Two species of haplochromine cichlid fishes of the genus Diplotaxodon Trewavas, endemic to Lake Malaŵi are described: Diplotaxodon longimaxilla, new species, and Diplotaxodon altus, new species. Diplotaxodon altus is diagnosed from other species in the genus based on body depth (35.1–37.8% SL), number of gill rakers (21–26), and a smaller cheek depth (18.2–20.0% HL). Diplotaxodon longimaxilla is delimited from other Diplotaxodon spp. based on body depth (28.9–32.4% SL), horizontal eye diameter (HED 27.1–32.1% HL), smaller cheek depth (15.2–19.4% HL), and number of lateral-line scales (35–38). Other authors have indicated that several other Diplotaxodon spp. occur, but too few specimens were available to permit detailed comparisons. The two new species occur sympatrically at depths of between 40–130 m. Specimens of Diplotaxodon altus were sampled from nets deployed at night using light attraction, while specimens of D. longimaxilla were sampled from nets operated both at night and day. We further ...

A New Species of Logperch Endemic to Tennessee (Percidae: Etheostomatinae:Percina)

Abstract Percina apina, the Tennessee Logperch, is described as a new species endemic to Tennessee and distributed in the Duck River system and Whiteoak Creek. The earliest collection records for Percina apina date to 1971 and the species was identified as Percina burtoni, the Blotchside Logperch. A phylogenetic analysis of mitochondrial DNA (mtDNA) published in 2006 showed that populations identified as Percina burtoni in the Duck River system and Whiteoak Creek were a new and undescribed species. In this study, we test the hypothesis that Percina burtoni is composed of multiple species through analyses of mtDNA, nuclear genetic variation, and traditional meristic trait morphology. Our analyses of morphological divergence, nuclear genotypes, mtDNA gene trees, and comparisons with other sister species pairs of logperches confirm the distinctiveness of Percina apina. Morphologically, Percina apina is distinguished from Percina burtoni through higher average numbers of lateral line scales (93.1 versus 89.9)...

Morphological comparison of Delminichthys ghetaldii (Steindachner, 1882), D. adspersus (Heckel, 1843), D. jadovensis (Zupančič & Bogutskaya, 2002) and D. krbavensis (Zupančič & Bogutskaya, 2002), endemic species of the Dinaric karst, Croatia

The objectives of this study were to gain a new understanding of the morphology of four endemic Delminichthys species, to determine the presence of morphological differences among populations and species, and to reveal reductive characters that might be connected with underground migrations. Morphometric and meristic characters were measured and statistically compared between populations and species. The study was conducted in the Dinaric region of Croatia and Bosnia and Herzegovina in the year 2013. Interpopulation variability observed for body shape (all size-independent morphometric characters significantly differed among populations) could be a reflection of the varying ecological conditions, although it might also imply the isolation of populations belonging to the same species. The number of lateral line scales (21–37 in D. krbavensis, 47–63 in D. jadovensis, 52–74 in D. adspersus, 88–105 in D. ghetaldii) proved to be the best diagnostic character for the Delminichthys species. Nevertheless, differences among the species in the number of pectoral and ventral fin rays, colouration, appearance of the lateral line, position of the mouth and presence of the groove above the upper lip were also observed.

New record of Spotstripe snapper, Lutjanus ophuysenii (Perciformes: Lutjanidae) from Korea

Three specimens of Lutjanus ophuysenii (217.8–226.7 mm in standard length) were collected by a gill net at Korea between August 2015 and July 2016. This species has not previously been recorded from Korea. L. ophuysenii is very similar to Lutjanus vitta. But several morphological characteristics distinguish the two species, including the number of lateral line scales (46–49 scales in L. ophuysenii; 49–52 scales in L. vitta), a black spot in the middle part of the longitudinal stripe (present in L. ophuysenii; absent in L. vitta), and the absence of a scale on posterior end of the preopercle in L. ophuysenii (present in L. vitta). The Korean name proposed for L. ophuysenii is “Jeom-jul-tung-dom.”

Morphometric and meristic characterization of the endemic Desert chub Gila eremica (Teleostei: Cyprinidae), and its related congeners in Sonora, Mexico

The Desert chub, Gila eremica DeMarais, 1991 is a freshwater fish endemic to Northwest Mexico, being described from the Sonora, Matape and Yaqui River basins in Sonora, Mexico. The recent discovery of 2 isolated small populations from the known distribution for this taxon makes necessary an evaluation to determine their specific taxonomical identities (herein designated as G. cf. eremica). Thirty-three morphometric and 6 meristic characters were evaluated in 219 specimens of several populations of the genus Gila in Sonora, including all the known populations of G. eremica. Morphometric measures based on box-truss protocol were standardized by regression models, and analyzed by means of a discriminant function analysis (DFA). The canonical variables 1 and 2 explained 72.4% of the total variation among analyzed populations. Tree diagram based on squared Mahalanobis distances, as well as scatterplots of centroids, showed G. cf. eremica to be morphologically divergent with respect to known populations of G. eremica as well as the other species analyzed. Box plots indicated a slimmer body and a smaller number of pectoral fin rays, and a higher number of lateral line scales as the most distinguishable characters in G. cf. eremica with respect to nominal G. eremica.

Pempheris gasparinii, a new species of sweeper fish from Trindade Island, southwestern Atlantic (Teleostei, Pempheridae).

Pempheris gasparinii sp. n. is described from five specimens, 59.1–68.0 mm in standard length. It is only known to occur in the shallow reefs of Trindade Island, 1200 km east of the Brazilian coast, in the southwestern Atlantic. Pempheris gasparinii is the third recognized species of Pempheris in the Atlantic Ocean. This new species is morphologically similar to its close relative, Pempheris poeyi, differing by the number of lateral-line scales (51–54 in Pempheris gasparinii vs. 47–49 in Pempheris poeyi), scales below lateral line (10–11 vs. 9), circumpeduncular scales (11–12 vs. 13), head and caudal peduncle lengths (2.7–3.3 vs 3.5–4.0 in head length). Moreover, Pempheris gasparinii shows a 4% genetic divergence from Pempheris poeyi at the cytochrome oxidase I locus (COI), consistent with a lineage split at the beginning of the Pleistocene. This new species represents the 12th endemic fish species from Trindade Island.

New Record of Brama dussumieri (Pisces: Bramidae) from Korea, as Revealed by Morphological and Molecular Analyses

Ten specimens of Brama dussumieri (family Bramidae) were collected from waters off Jeju Island, Busan, and Gangneung, Korea, during 2013-2014. The specimens were characterized by having 58-64 lateral line scales and 13-15 gill rakers. An analysis of 567 base pair sequences of mitochondrial DNA cytochrome c oxidase subunit I showed that sequences in our ten specimens are concordant with those of B. dussumieri from the USA, India, and Japan, although with slight differences (genetic distance = 0.000-0.018). Brama dussumieri was distinguished from the most similar species, Brama japonica, by the number of lateral line scales (57-65 in B. dussumieri vs. 65-75 in B. japonica) and the number of gill rakers (13-15 in B. dussumieri vs. 17-20 in B. japonica). We propose the new Korean name "Wae-sae-da-rae" for B. dussumieri in Korea.

Innervation of the lateral line system in the blind cavefish Astyanax mexicanus (Characidae) and comparisons with the eyed surface-dwelling form

The lateral line system and its innervation were examined in the blind cavefish Astyanax mexicanus (Characidae) and compared with that in the eyed surface-dwelling form of the same species. In both forms, superficial neuromasts occurred on almost the entire surface of the body and caudal fin, the number in the blind form being greater on the head (831) and tail (511) than in the eyed form (531 and 251, respectively), but lower on the trunk (1,305 vs. 2,125). In the blind form, superficial neuromasts were greatly proliferated on the cheek and lower jaw, the mandibular ramus being extensively ramified, including an additional major ramule that was absent in the eyed form. In both forms, superficial neuromasts on the trunk were innervated by a number of dorsal and ventral ramules (roughly corresponding to the number of lateral line scales) derived from the lateral ramus. In both forms, canal neuromasts in the infraorbital and trunk lateral line canals were innervated by nerves without associated elements innervating superficial neuromasts. Accordingly, the lateral line scales each accommodated only a single canal neuromast. This lateral line scale condition was recognized as common in Characidae, being in sharp contrast to the condition in Cyprinidae (both included in Otophysa) in which the lateral line scales each had a vertical row of superficial neuromasts.

Neoniphon pencei, a new species of holocentrid (Teleostei: Beryciformes) from Rarotonga, Cook Islands

Neoniphon pencei, n. sp., is described from thirteen specimens, 132-197 mm standard length (SL) collected from mesophotic coral ecosystems (MCEs) at Rarotonga, Cook Islands by divers using mixed-gas closed-circuit rebreathers. It differs from all other species of the genus in number of lateral line scales, scales above and below lateral line, elements of life color, and in COI and cytochrome b DNA sequences. Of the five other known species of Neoniphon, it is most similar to the Indo-Pacific N. aurolineatus and the western Atlantic N. marianus both morphologically and genetically.