Caudal-fin Rays Research Articles

Schistura andrewi, a new species of loach (Teleostei: Nemacheilidae) from Mizoram, northeastern India.

Schistura andrewi, a new species of loach, is described from a tributary of Kaladan River in Mizoram, northeastern India. It is distinguished from its congeners in having the following combination of characters: long axillary pelvic lobe; complete lateral line with 82-95 pores; 2 unbranched dorsal and anal fin rays; 6-7 broad, wider than interspace, black bars on the body; 2 rows of black spots horizontally across the dorsal fin; a deeply emarginate caudal fin, with 2 vertical rows of black spots across the fin, and 9 + 8 branched caudal fin rays.

In-vivo imaging of the fracture healing in medaka revealed two types of osteoclasts before and after the callus formation by osteoblasts

The fracture healing research, which has been performed in mammalian models not only for clinical application but also for bone metabolism, revealed that generally osteoblasts are induced to enter the fracture site before the induction of osteoclasts for bone remodeling. However, it remains unknown how and where osteoclasts and osteoblasts are induced, because it is difficult to observe osteoclasts and osteoblasts in a living animal. To answer these questions, we developed a new fracture healing model by using medaka. We fractured one side of lepidotrichia in a caudal fin ray without injuring the other soft tissues including blood vessels. Using the transgenic medaka in which osteoclasts and osteoblasts were visualized by GFP and DsRed, respectively, we found that two different types of functional osteoclasts were induced before and after osteoblast callus formation. The early-induced osteoclasts resorbed the bone fragments and the late-induced osteoclasts remodeled the callus. Both types of osteoclasts were induced near the surface on the blood vessels, while osteoblasts migrated from adjacent fin ray. Transmission electron microscopy revealed that no significant ruffled border and clear zone were observed in early-induced osteoclasts, whereas the late-induced osteoclasts had clear zones but did not have the typical ruffled border. In the remodeling of the callus, the expression of cox2 mRNA was up-regulated at the fracture site around vessels, and the inhibition of Cox2 impaired the induction of the late-induced osteoclasts, resulting in abnormal fracture healing. Finally, our developed medaka fracture healing model brings a new insight into the molecular mechanism for controlling cellular behaviors during the fracture healing.

A new genus of cardinalfish from tropical Australia and southern New Guinea (Percomorpha: Apogonidae).

Ozichthys is described as a new monotypic genus, type species Apogon albimaculosus. This species is restricted to tropical Australia and southern New Guinea. The combination of first dorsal fin with VIII visible spines, fused first and second hypurals, epineural on ninth rib, ossified lower preopercle edge, serrated edge of the preopercle, more than three flute canals on post orbit, 23-24 pored lateral- line scales, elongate last lateral-line scale, and sixteen rows of free neuromasts on principal caudal fin-rays will identify this genus from other brownish ground-colored apogonids. This genus is placed in the clade with Apogonichthys, Foa, Fowleria, and Neamia based on color patterns present on the head, body and vertical fins and in having a single pore above and below the raised median canal on each pored lateral-line scale.

Review of the species of the genus Serrapinnus Malabarba, 1998 (Teleostei: Characidae: Cheirodontinae) from the rio Tocantins-Araguaia basin, with description of three new species.

Species of the genus Serrapinnus from the rio Tocantins-Araguaia basin are revised and three new species are described. Serrapinnus aster new species is diagnosed by the presence of scimitar-shaped ventral procurrent caudal-fin rays of mature males forming a semicircle and by the presence of 7-9 cusps on the premaxillary teeth; S. lucindai new species is distinguished from its congeners by the presence of a higher number of ventral procurrent caudal-fin rays (17 to 19); and S. tocantinensis new species differs from the remaining species of the genus by the elongation of the unbranched dorsal and pelvic-fin rays into filaments in mature males. Serrapinnus sterbai is recognized as broadly distributed in the Tocantins-Araguaia basin and is redescribed based on specimens from across its entire distribution. A key for the cheirodontines occurring in the Atlantic drainages of northeastern Brazil, from the rio Tocantins-Araguaia to the rio Paraguaçú is provided.

Three new species of Trimma (Pisces; Gobioidei) from Indonesia.

Three new species of Trimma are described from various localities in Indonesia. All three can be readily identified from their live, freshly collected, or preserved colouration. Trimma meranyx n. sp. is further distinguished from other species by the possession of 8-9 scales in the predorsal midline, up to three rows of (usually) cycloid scales on the opercle, two scales at the posterodorsal border of the cheek, a very slightly elongate second dorsal spine which only just reaches the spine or anterior rays of the second dorsal fin, unbranched pectoral fin rays, a fifth pelvic fin ray that branches once and is 64-85% the length of the fourth ray, and a full basal membrane connecting the inner branches of the two fifth pelvic rays. The dark red (live) or black posterior half of the caudal peduncle with large white spots straddling the dorsal and ventral midlines just anterior to the first procurrent caudal fin rays is the diagnostic colour character. The species is known from North Sulawesi, West Papua (Raja Ampat and Fakfak), and the south-eastern tip of Papua New Guinea, with possible records from the Philippines and Vanuatu. Trimma pajama n. sp. has 6 scales in the predorsal midline, two ctenoid scales along the dorsal margin of the opercle, a slightly elongate second dorsal spine reaching posteriorly to the base of the spine or first ray of the second dorsal fin, unbranched pectoral fin rays, a fifth pelvic ray with a single branch point and which is 58-72% the length of the fourth ray, and a full basal membrane connecting the inner branches of the two fifth pelvic rays. The live, freshly collected and preserved colour pattern of alternating dark and light stripes on the head and most of the body (except the posterior half of the caudal peduncle) is diagnostic. It is currently known from West Papua (Raja Ampat and Fakfak) and the southern tip of Papua New Guinea, with possible records from Kalimantan (Indonesia), Palau, the Hermit Is (Papua New Guinea) and the Solomon Islands. Trimma zurae n. sp. has 8-9 scales in the predorsal midline, usually a single row of cycloid scales along the upper border of the opercle, 11 anterior and 9 posterior transverse scale rows, no elongated spines in the first dorsal fin, 9 dorsal and 8 anal fin rays, the middle rays of the pectoral fin branched, a single branch in the fifth pelvic fin ray which is 65-76% the length of the fourth ray and a reduced basal membrane of < 20% the length of the fifth ray. The eye-diameter sized black ocellated spot between the first to fifth spines of the first dorsal fin is diagnostic, as are the pupil-diameter sized orange spots on the nape, opercle and posterodorsal part of the cheek. It is currently known only from a single locality just west of Manado, Sulawesi.

Devario deruptotalea, a new species of cyprinid fish from Manipur, India (Teleostei: Cyprinidae).

Devario deruptotalea, a new cyprinid fish, is described from Dutah Stream, a tributary of the Yu River (Chindwin drainage) in Manipur, India. It is distinguished from all its congeners by a unique colour pattern consisting of the following combination of pigmented elements: 4‒6 dark brown irregularly shaped and arranged bars that are partly confluent with adjacent bars at different levels on the anterior one-third of the side of the body, followed by three distinct dark brown stripes posteriorly, a P stripe that is darker and about twice as broad as other stripes and extending to the tip of the median caudal-fin rays.

Use of tetracycline hydrochloride and alizarin complexone for immersion marking black rockfish Sebastes schlegelii

We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30–40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of 200–400 mg/L, 250–400 mg/L, and 250–400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (≥350 mg/L TC, ≥250 mg/L ALC for scales and ≥350 mg/L TC, ≥300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350–500 mg/L, and ALC between 300–400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking (P > 0.05).

Olyra saginata, a new species of bagrid catfish (Actinopterygii: Siluriformes) from northeastern India.

Olyra saginata, new species, is described from the Kaladan [=Kolodyne] River system in Mizoram, northeast India. It differs from congeners in having the following unique combination of characters: interorbital distance 27.9-35.9% HL; 54-66 lateral-line pores; body depth at anus 10.5-12.0% SL; length of adipose-fin base 17.3-22.4% SL; adipose fin separate from upper principal caudal-fin rays; post-adipose distance 11.8-14.3% SL; caudal peduncle length 14.8-17.7% SL; and caudal peduncle depth 7.8-8.9% SL. The taxonomy of congeners is also briefly discussed.

Combining morphology and genetics in resolving taxonomy--a systematic revision of spined loaches (Genus Cobitis; Cypriniformes, Actinopterygii) in the Adriatic watershed.

Taxonomic investigation of spined loaches from Dalmatia and Herzegovina was conducted on specimens from 14 localities. The results of the detailed morphological investigations were combined with genetic data (based on one mitochondrial and two nuclear genes) in order to resolve the taxonomic status of each Cobitis population. Among the investigated features of external morphology, the appearance of spots on the caudal fin base turned out to have the greatest diagnostic value. Furthermore, the number of branched fin rays enabled the discrimination of several species. No morphometric character alone could ensure determination of any Cobitis species. Nevertheless, groups of populations that are more similar in their body shapes correspond to mitochondrial phylogenetic lineages. Based on molecular genetic markers, Dalmatian and Herzegovinian spined loaches form independent lineages inside the Adriatic phylogenetic group. Mitochondrial DNA phylogenetic reconstruction revealed six monophyletic lineages, corresponding to six species distributed in the investigated area. The population distributed in Mostarsko blato karstic field in Bosnia and Herzegovina is described as a new species based on a unique combination of morphological characters: a single triangular Canestrini scale; usually 51/2 branched anal fin rays, 61/2 branched dorsal fin rays, 14 branched caudal fin rays; no spots in the surface pigmentation layer on the caudal fin base; scales on the body very small.

Hemigrammus ataktos: a new species from the rio Tocantins basin, central Brazil (Characiformes: Characidae)

A new species of Hemigrammus is described from the middle rio Tocantins basin, central Brazil. The new species can be distinguished from all congeners by having a black midlateral stripe on the body extending from the posterior margin of the eye to the median caudal-fin rays. Mature males possess dorsal-, pelvic-, and anal-fin rays elongate, features that also help to recognize the new species. Although the new species is described in Hemigrammus, some specimens present a complete series of pored scales in the lateral line. A discussion about the generic allocation of the new species is presented.

New species of Cyphocharax (Characiformes: Curimatidae) from the upper rio Negro, Amazon basin

A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

Moenkhausia rubra, a new species from rio Juruena, upper rio Tapajós basin, Brazil (Characiformes: Characidae)

Moenkhausia rubra, new species, is described from the upper rio Juruena, rio Tapajós basin, Mato Grosso, Brazil. The new species is distinguished from its congeners, except M. hemigrammoidesand M. nigromarginata, by the dark pigmentation on the anteriormost rays of both dorsal and anal fins. Moenkhausia rubrais distinguished from the aforementioned species by the number of branched anal-fin rays 17-20 (vs. 20-25), presence of a dark blotch on the caudal peduncle extending to middle caudal-fin rays, absence of longitudinal black zigzag stripes between longitudinal rows of scales on body, and other details of coloration.

A new species of Serrapinnus Malabarba, 1998 (Characidae: Cheirodontinae) from Rio Grande do Norte State, northeastern Brazil

Serrapinnus potiguar, new species, is described from the rio Ceará-Mirim, a coastal drainage in the Rio Grande do Norte State, northeastern Brazil. The new species is distinguished from the other species of the genus by the shape and arrangement of the ventral procurrent caudal-fin rays of the sexually dimorphic males; where the hypertrophied elements present the shape of a series of scimitars arranged radially, forming a semi-circle on the ventral margin of the caudal peduncle. Furthermore, the new species is diagnosed from S. heterodonand S. piaba, sympatric congeners from the northeastern Brazilian drainages, respectively by the presence of incomplete lateral line and teeth bearing at most five cusps.

Chrysobrycon yoliae, a new species of stevardiin (Characiformes: Characidae) from the Ucayali basin, Peru

Chrysobrycon yoliae, new species, is described from a drainage flowing into the río Yucamia basin, río Ucayali basin, Peru. Chrysobrycon yoliaeis readily distinguished from its congeners by the anterior tip of pelvic bone situated anterior to the fifth rib (vs. situated posterior to the fifth rib), the presence of 20-26 dentary teeth (vs. 11-19), and the possession of a terminal lateral-line tube between caudal-fin rays 10 and 11 (vs. the absence of this tube, except in C. eliasi). The new species differs from C. eliasiand C. myersiby the presence of teeth on third pharyngobranchial (vs. the absence of teeth on this bone) and also differs from C. eliasiby the dorsal-fin origin situated at vertical through anal-fin rays 5 to 7 (vs. located at vertical through anal-fin rays 8 to 10), the posterior extent of the ventral process of quadrate reaching the vertical through posterior margin of symplectic (vs. not reaching the vertical through posterior margin of symplectic), the dorsal-fin to adipose-fin length 26.8-28.8% SL (vs. 23.9-26.8% SL), and the body depth at dorsal-fin origin 34.4-42.2% SL (vs. 24.1-34.5% SL). A key for the identification of Chrysobryconspecies is provided.

Feeding effect of selenium enriched rotifers on larval growth and development in red sea bream Pagrus major

Abstract Feeding trials were conducted to investigate the effect of selenium (Se)-enriched rotifers on growth and development of red sea bream Pagrus major larvae. Fish were reared from fertilized eggs (98% hatch rate) to 20 days post hatch (dph) at 19 °C with two different food sources; non-enriched S-type rotifers (0.0 μg Se/g D.W., control diet) or Se-enriched rotifers (2.2 μg Se/g D.W., Se-enriched diet) at 10 rotifers/mL, respectively. On the last day of larviculture, the Se-enriched diet accelerated growth and developmental stage of fish larvae. The larvae fed Se-enriched rotifers were advanced in the following parameters compared to those fed control diet: total length (6.06 vs 5.53 mm), standard length (5.74 vs 5.26 mm), head length (1.46 vs 1.28 mm), eye diameter (0.57 vs 0.50 mm), the number of caudal fin rays (5.8 vs 1.9), and the proportion of individuals undergoing notochord flexion (55 vs 3%). Fish larvae of 20 dph showed higher Se concentration (9.5 ± 0.2 μg/g DW) with the Se-enriched diet than with the control diet (1.3 ± 0.3 μg/g DW), but there were no significant differences in the composition of polyunsaturated fatty acids which significantly affect larval growth and development. Therefore, the feeding of Se enriched rotifers enhanced growth and development of the red sea bream P. major larvae.

Re-description of Trichomycterus cubataonis BIZERRIL, 1994 (Siluriformes: Trichomycteridae) from the Cubatão river basin, southern Brazil

Trichomycterus cubataonis, from the Cubatão river, southern Brazil, is re-described and revalidated. It is hypothesized as closely related to T. diabolus, T. itatiayae, T. maculosus and T. nigroautarus based on the presence of a broad metapterygoid, which is wider than deeper. Trichomycterus cubataonis differs from the above four species by the number of pectoral, dorsal, and anal-fins rays, origin of anal fin related to the dorsal-fin base, insertion of pelvic-fin related to the vertebrae, origin of dorsal- and anal fins related to the vertebrae, number of dorsal and ventral procurrent rays of caudal fin, number of odontodes of the opercular and interopercular patch, length, depth and width of the head, and eye size. Moreover, T. cubataonis differs from T. zonatus mainly by the insertion of pelvic-fin related to the vertebrae, origin of dorsal- and anal fins related to the vertebrae, number of anal fin rays, and the position of the anal fin related to the dorsal-fin base. Therefore, T. cubataonis should be considered a valid species.

A new genus of miniature cynolebiasine from the Atlantic Forest and alternative biogeographical explanations for seasonal killifish distribution patterns in South America (Cyprinodontiformes: Rivulidae)

The analysis of 78 morphological characters for 16 species representing all the lineages of the tribe Cynopoecilini and three out-groups, indicates that the incertae sedis miniature species ‘Leptolebias’ leitaoi Cruz & Peixoto is the sister group of a clade comprising the genera Leptolebias, Campellolebias, and Cynopoecilus, consequently recognised as the only member of a new genus. Mucurilebias gen. nov. is diagnosed by seven autapomorphies: eye occupying great part of head side, low number of caudal-fin rays (21), distal portion of epural much broader than distal portion of parhypural, an oblique red bar through opercle in both sexes, isthmus bright red in males, a white stripe on the distal margin of the dorsal fin in males, and a red stripe on the distal margin of the anal fin in males. Mucurilebias leitaoi is an endangered seasonal species endemic to the Mucuri river basin. The biogeographical analysis of genera of the subfamily Cynolebiasinae using a dispersal-vicariance, event-based parsimony approach indicates that distribution of South American killifishes may be broadly shaped by dispersal events. The analysis supports south-eastern Brazilian coastal plains as the centre of dispersal for cynolebiasine killifishes. Alternative biogeographical explanations are compared and possible dispersal routes and means of dispersal are discussed.

New Species ofNannocharax(Characiformes: Distichodontidae) from the Northwestern Congo River Basin, with an Appraisal ofHemigrammocharax

Nannocharax hastatus, new species, is described from the Lékoli River in the Likouala River system, Pool Malebo, and the Luilaka and Tshuapa rivers of the Momboyo river basin in the northwestern and central portions of the Congo River basin. The new species shares with N. ocellicauda and N. maculicauda a distinctive coloration pattern of a nearly completely unpigmented body other than for dark lines along the bases of the anal and dorsal fins and a longitudinally elongate, ovoid, dark spot on the posterior portion of the caudal peduncle and basal region of the central caudal-fin rays. That pigmentation pattern is unique to these three species in what was defined as the Hemigrammocharax–Nannocharax clade. In addition to coloration the three species share a distinctive overall elongate form of the head and body. Nannocharax hastatus differs from N. ocellicauda and N. maculicauda in the extent of poring along the lateral line and number of lateral line and circumpeduncular scales. Variation in the degree of poring of the lateral line in the species complex formed by these three species provides further evidence that the feature used-to-date to delimit Hemigrammocharax from Nannocharax—the extent of poring along the lateral line—fails to define monophyletic assemblages, and Hemigrammocharax is placed into the synonymy of Nannocharax which now forms a monophyletic assemblage.

A new species of Astyanax Baird & Girard (Characiformes: Characidae) from the Rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil, with comments on bony hooks on all fins

A new species of Astyanax from the Rio Paraguaçu basin, Bahia, Brazil, is described. This new species is distinguished from its congeners known to occur in Brazilian drainages by the presence of small bony hooks on all fins of mature males. Furthermore, the new species can be diagnosed by its colour pattern, which consists of a unique vertically elongated humeral blotch, a conspicuous dark drop-shaped horizontal blotch over the caudal peduncle, tapering anteriorly and not extending to the median caudal-fin rays, and by the absence of a conspicuous broad dark midlateral stripe. The new species differs further by having the greatest body depth just anterior to the dorsal-fin origin, 32-35 perforated scales in the lateral line and a reduced number of branched anal-fin rays (16-20). Apparently, the new species does not fit into any species complex of Astyanax. The occurrence of bony hooks on all fins of Astyanax is discussed.

Morphological observation and length-weight relationship of critically endangered riverine catfish Rita rita (Hamilton).

The experiment was conducted to investigate the morphological status of the critically endangered riverine catfish Rita rita using morphometric and meristic traits. About 158 species of Rita were collected from the old Brahmaputra river in Mymensingh district and were studied in the laboratory of the Fisheries Biology and Genetics Department, Bangladesh Agricultural University. Measurement of length and weight of Rita were recorded by using measuring scale and electric balance respectively. Significant curvilinear relationship existed between total length and other morphometric characters and between head length and other characters of the head. Relationships between total length and various body measurements of the fish were highly significant (p < 0.01) except the relationship between total length and pelvic fin length of male fish (p < 0.05). In case of meristic characters-dorsal fin rays, pelvic fin rays, pectoral fin rays, anal fin rays, caudal fin rays, number of vertebrae and branchiostegal rays were found to be more or less similar except slight differences. The values of condition factors (k) in the total length body-weight relationships for female and male were found to be 0.41 and 0.38, respectively. The mean values of relative condition factors (kn) were 1.0 and 1.005 for female and male, respectively.