Number Of Dorsal Fin Rays Research Articles

Morpho-meristic characteristics and growth pattern of walking snakehead (Channa orientalis) collected from different locations of Northwestern Bangladesh

This study aimed to reveal the morphometric and meristic variations, length-weight relationships, and condition factor of Channa orientalis collected from three regions (Kurigram, Rangpur, and Lalmonirhat districts) of Northwestern Bangladesh. Fifteen morphometric and six meristic characteristics were selected. Eight morphometric characteristics were significantly different (p<.05) among the regions; three characteristics were highly significant (p<.001) in Kurigram (Pre-orbital distance, PrOD; Lower-jaw length, LJL; Upper-jaw length, UJL) indicating C. orientalis population of Kurigram was significantly different (p<.001) from the other two locations. On the other hand, among six meristic characteristics, number of dorsal fin rays (DFR), pectoral fin rays (PFR), anal fin rays (AFR), and branchiostegal rays (BR) were found to be significantly different among three locations. The values of PFR varied significantly (p<.05) in Kurigram, which distinguishes the other two regions. Likewise, DFR and BR showed significant variations in the Rangpur region, whereas AFR significantly (p<.001) separated the Lalmonirhat population from the others. In length-weight relationships, the generalized relationship between total length (TL) and body weight (BW) were BW=0.007TL3.147 (r2=0.945), BW=0.03TL2.573 (r2=0.916) and BW=0.008TL3.084 (r2=0.899) for Kurigram, Rangpur, and Lalmonirhat, respectively. The growth pattern showed positive allometric in Kurigram (b=3.14) and Lalmonirhat (b=3.08). Negative allometric was observed in Rangpur (b=2.57). The study exhibited a higher condition factor (K) value in Kurigram (1.068) and Rangpur (1.049) whereas the lowest in Lalmonirhat (0.978). The study reveals that the C. orientalis population`s morpho-meristic and growth status were comparatively better in Kurigram region.

Taxonomic review of the rare oarfish Regalecus russellii (Regalecidae: Lampriformes) from Korea using morphological and molecular methods

One of the largest bony fishes on earth, the family Regalecidae is very rare. So, they remain largely unknown. They are often misidentified each other because they tend to be usually found in a damaged condition. Therefore, we firstly provide detailed morphological traits of R. russellii based on three voucher specimens (total length, 170–422 cm; damaged bodies) collected from Uljin, Ulsan and Jeju-do Island, Korea during 2018–2022. Based on color patterns, the numbers of dorsal fin rays, and gill rakers, our specimens were identified as R. russellii. The morphology of our specimens nearly matched that of the Eastern Pacific R. russellii. Molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit I (506 bp) sequences showed that our specimens almost matched R. russellii recorded from Taiwan (Kimura-2-parameter distance = 0.44%). Our detailed morphological and molecular analysis results highlight the importance of voucher specimens to prevent misidentification.

COMPARATIVE MORPHOMETRIC, MERISTIC AND OSTEOLOGICAL STUDIES ON ADULT AND YOUNG HILSA (TENUALOSA ILISHA)

Tenualosa ilisha (matured/adult) and jatka (immature/young), locally known as Ilish, is designated as the national fish of Bangladesh. Both the stages were collected from different fish markets from Savar, Bangladesh during the exploration. This study was carried out on comparative morphometric, meristic and osteology between the Tenualosa ilisha (matured) and jatka (immature/young). The morphometric characteristics were higher in matured Tenualosa ilisha than immature jatka and among them head length, pre-dorsal length, postorbital length, the height of anal fin, eye diameter length, and abdominal region length were found significantly different. The proportion of standard length and snout length, head length and snout length, abdominal region length and standard length were significantly different between the two stages. Among the meristic characteristics; number of dorsal fin rays, anal fin rays and scales on the lateral line were found with little differences between matured hilsa and jatka. There are very small differences in the number of scales, scutes and fin rays of different fins between the two stages of fishes. The osteological comparison reveals more or less identical structure. Most of the bones of the skull were similar in structure but differed in size, shape and thickness.

A new species of cloud fish of the genus Hypsolebias from Northeast Brazil (Cyprinodontiformes: Rivulidae)

Abstract A new species of cloud fish of the genus Hypsolebias is described from a temporary pool in the rio Trairi basin, Rio Grande do Norte State, Brazil. It is the first record of the genus Hypsolebias for the basin. The new speciesbelongs to the H. flammeus species-group, which is composed of the species H. alternatus, H. brunoi, H. delucai, H. fasciatus, H. longignatus, H. marginatus, H. multiradiatus, and H. flammeus. The new species differs from all other species of the group, except H. flammeus, H. multiradiatus,and H. brunoi, by male color pattern and the presence of a metallic blue sheen surrounding the black spots of females. It differs from H. flammeus, H. multiradiatus and H. brunoi by dorsal and anal fin shape (both rounded vs. pointed) and by the orientation of the reddish-brown bars on the body and anal fin of males (diagonal vs. vertical). The new species differs from its congeners of Northeast Brazil mainly by the higher number of dorsal fin rays in males and the higher number of scales in the longitudinal series.

The monophyly of Crenuchinae and description of two new species ofPoecilocharax(Teleostei: Crenuchidae) based on phenotypic and genotypic evidence

AbstractCrenuchinae is a subfamily of the fish family Crenuchidae distributed in the Amazon Basin with pronounced sexual dimorphism and exuberant colour patterns. Recent fieldwork in the tributaries of the Rio Aripuanã drainage, a large tributary of the Rio Madeira (Amazon Basin), resulted in the discovery of two distinctive, undescribed species of the crenuchin genus Poecilocharax, which are formally described herein, combining morphological and molecular data. These are the first representatives of Crenuchinae discovered after a gap of 57 years and the first records of Poecilocharax from the tributaries of the right bank of the Rio Amazonas draining the Brazilian crystalline shield. Based on a taxonomic review including all species of the subfamily, we provide an expanded morphological diagnosis for Crenuchinae. This now includes characteristics related to the lateral-line canals of head and body, the number of dorsal-fin rays and sexually dimorphic traits. In addition, we review previous characteristics used to diagnose Crenuchus and Poecilocharax, providing comments on their polarity and distribution across the subfamily. A dichotomous key is provided for the first time for species of Crenuchinae.

Early development of two commercially valuable fish from the lower Amazon River, Brazil (Characiformes: Serrasalmidae)

Abstract We described the early development of Myloplus asterias and M. lobatus, two fish species of the Serrasalmidae using morphological, meristic, and morphometric characteristics. These herbivores serrasalmids are heavily fished because of their commercial importance in the Amazon. The individuals were collected between 2016 and 2020 in the limnetic zone of open water and macrophyte stands in the Lower Amazon River floodplain. We tested different growth models to identify the development pattern of these species. During the initial ontogeny, these two species can be differentiated mainly by the myomeres total number, 37 to 39 in M. asterias vs. 40 to 41 in M. lobatus, the pigmentation pattern, and dorsal-fin ray numbers. These characteristics are effective in distinguishing these species from other serrasalmids. The morphometric relationships were also different between these two species, showing distinct patterns in growth between the analyzed features. An identification key for larvae of some sympatric Serrasalmidae species from the Amazon basin is presented. Our expectation is that this study will contribute to the knowledge of the initial ontogeny and the biology of fish species in the Neotropical region.

A new candiru of the genus Paracanthopoma (Siluriformes: Trichomycteridae) from the Araguaia River basin, central Brazil.

A new species of the candiru genus Paracanthopoma is described from the floodplains of the Bananal Island, a transition area between the Cerrado and Amazon, in the Araguaia River basin, central Brazil. Paracanthopoma cangussu sp. nov. is distinguished from its congeners, Paracanthopoma parva and Paracanthopoma saci, by the presence of seven opercular odontodes, five dentary teeth, five median premaxillary teeth, and first dorsal-fin pterygiophore in a vertical through the centrum of the 23th or 24th vertebra. It is further distinguished from each congener by an exclusive combination of character states, comprising the number of vertebrae, number of precaudal vertebrae, number of dorsal procurrent caudal-fin rays, number of ventral procurrent caudal-fin rays, number of dorsal-fin rays, disposition of pores on the cephalic portion of the latero-sensory system, absence of an anterior process on the anterior margin of parieto-supraoccipital, number of dorsal-fin pteryigiophores and number of interopercular odontodes. Although vandelliines are known for being exclusively hematophagous, with guts gorged with blood, two cleared and stained specimens of P. cangussu sp. nov. had Chironomidae larvae (Insecta) on their guts. Because most specimens of P. cangussu sp. nov. were collected with stomachs filled with blood, it was hypothesized that the species feeds accidentally or occasionally on insects.

A New Cryptic Species of Polymixia (Teleostei, Acanthomorpha, Polymixiiformes, Polymixiidae) Revealed by Molecules and Morphology

A new and previously cryptic fish species, Polymixia hollisterae, new species, proposed common name “Bermuda Beardfish,” is described from two voucher specimens collected in 1997 at a depth of about 280 fm or 512 m on the NW slope of the Bermuda Platform, and a third voucher collected by a midwater trawl in the north-central Gulf of Mexico. The species belongs to the paracanthopterygian acanthomorph genus Polymixia, family Polymixiidae, order Polymixiiformes, and is named after pioneering ichthyologist, ocean explorer, and conservationist Gloria E. Hollister (Anable). It is distinguished from all other species in the genus by its greater dorsal and anal fin heights (19% and 14% of SL, respectively), its extremely long pectoral and pelvic fins (22% and 14% of SL, respectively), its relatively large eye diameter (34% of total head length), and its morphologically distinctive first anal-fin radial. It has a unique pigmentation pattern on the dorsal, anal, and caudal fins consisting of narrow, dark black patches near the tips of the longest few soft dorsal- and anal-fin rays, and a caudal-fin margin with a dark black fringe covering the distal fourth of the fin. Based on an earlier molecular study that revealed it to be a cryptic species, P. hollisterae, new species, is closely related to P. japonica, but it differs by 20–33 nucleotides in a total alignment of 4,983 nuclear and mitochondrial sites. The new species shares a distinctive scale morphology with P. japonica and P. nobilis (the type species); an intermediate number of dorsal-fin rays (V,31–32), like P. japonica (V,31–34); a distinctive preopercle shape with P. japonica, P. lowei, and P. berndti; and a low number of pyloric caeca with P. lowei and P. berndti. Pored lateral-line scales number 35, an intermediate number compared to reported counts of other species (31–39). The three supraneurals are sigmoid-shaped like those of P. nobilis, while dorsal-fin proximal radials interfinger with neural spines in a unique pattern. Body shape, as studied with measurement proportions and multivariate morphometrics, is distinguished by a relatively large head, large eyes, long jaws, and a more streamlined pre-dorsal body profile than its congeners. Further research and additional collecting will be needed to ascertain the geographic distribution and conservation status of the new species.

The Cyphomyrus Myers 1960 (Osteoglossiformes: Mormyridae) of the Lufira basin (Upper Lualaba: DR Congo): A generic reassignment and the description of a new species.

Within a comparative morphological framework, Hippopotamyrus aelsbroecki, only known from the holotype originating from Lubumbashi, most probably the Lubumbashi River, a left bank subaffluent of the Luapula River, is reallocated to the genus Cyphomyrus. This transfer is motivated by the fact that H. aelsbroecki possesses a rounded or vaulted predorsal profile, an insertion of the dorsal fin far anterior to the level of the insertion of the anal fin, and a compact, laterally compressed and deep body. In addition, a new species of Cyphomyrus is described from the Lufira basin, Cyphomyrus lufirae. Cyphomyrus lufirae was collected in large parts of the Middle Lufira, upstream of the Kyubo Falls and just downstream of these falls in the lower Lufira and its nearby left bank affluent, the Luvilombo River. The new species is distinguished from all its congeners, that is, firstly, from C. aelsbroecki, C. cubangoensis and C. discorhynchus, by a low number of dorsal fin rays, 27-32 (vs. higher, 36 (37), 34 (33-41) an 38 (38-40), respectively) and, secondly, from C. aelsbroecki, C. cubangoensis, and C. discorhynchus by a large prepelvic distance, 41.0-43.8% LS (vs. shorter, 39.7%, 38.9-39.1% and 37.0-41.0% LS , respectively). The description of yet another new species for the Upemba National Park and the Kundelungu National Park further highlights their importance for fish protection and conservation in the area. Hence, there is an urgent need for the full integration of fish into the management plans of these parks.

A new psammophilic species of the catfish genus Ammoglanis (Siluriformes, Trichomycteridae) from the Amazon River basin, northern Brazil

Ammoglanis obliquussp. nov., a minute catfish species reaching a maximum adult size of 15.5 mm, is described from the Rio Preto da Eva drainage in the central Brazilian Amazon. It is distinguished from all of its congeners in possessing an exclusive combination of character states, including the presence and number of premaxillary and dentary teeth, number of interopercular and opercular odontodes, presence of cranial fontanel, number of dorsal-fin rays, number of anal-fin rays, number of caudal-fin rays, number of pelvic-fin rays, number of pectoral-fin rays, absence of pelvic splint, antorbital morphology, and absence of supraorbital and autopalatine morphology. It is considered to be a member of a clade also including A. pulex and A. amapaensis due to the unique oral, antorbital, and autopalatine morphology. Ammoglanis obliquus is regarded as more closely related to A. pulex than to any other congener, as both species exhibit a similar colour pattern, an absence of the metapterygoid, and the presence of two finger-like projections on the chin region.

Leptonotus vincentae, a new pipefish species (Syngnathidae: Syngnathinae) from the south-west Atlantic Ocean near northern Patagonia.

A new species of pipefish Leptonotus vincentae sp. nov. (Syngnathidae) is described on the basis of 12 specimens found in shallow waters (<2 m depth) of San Antonio Bay, Patagonia, Argentina, in the south-west Atlantic Ocean. The species is distinguished from congeners by the combination of: dorsal-fin rays 30-33, pectoral-fin rays 12-13, trunk rings 18-19, tail rings 43-46, subdorsal rings (2-4) + (5.5-8) = (8.5-10), head length 13-14% standard length, snout length 35-55% head length and snout depth 21-30% in snout length. Although this species has often been mistaken for Leptonotus blainvilleanus, most diagnostic characters of the two species differ. Both species are clearly distinguished by their snout length. L. blainvilleanus has a relatively longer snout than L. vincentae sp. nov. The new species is similar to a south-west Pacific species, Leptonotus elevatus. However, L. vincentae sp. nov. differs from this species in that it exhibits a lower number of dorsal-fin rays and a relatively longer head.

Recently diverged killifishes: Morphometry and caudal skeleton osteology of two members of the Aphanius dispar species group (Aphaniidae, Teleostei)

Recently diverged killifishes: Morphometry and caudal skeleton osteology of two members of the Aphanius dispar species group (Aphaniidae, Teleostei)

Production of Tiger Puffer Takifugu rubripes Offspring from Triploid Grass Puffer Takifugu niphobles Parents.

The tiger puffer Takifugu rubripes is one of the most popular aquacultural fish; however, there are two major obstacles to selective breeding. First, they have a long generation time of 2 or 3years until maturation. Second, the parental tiger puffer has a body size (2-5kg) much larger than average market size (0.6-1.0kg). The grass puffer Takifugu niphobles is closely related to the tiger puffer and matures in half the time. Furthermore, grass puffer can be reared in small areas since their maturation weight is about 1/150 that of mature tiger puffer. Therefore, to overcome the obstacles of maturation size and generation time of tiger puffer, we generated surrogate grass puffer that can produce tiger puffer gametes through germ cell transplantation. Approximately 5000 tiger puffer testicular cells were transplanted into the peritoneal cavity of triploid grass puffer larvae at 1day post hatching. When the recipient fish matured, both males and females produced donor-derived gametes. Through their insemination, we successfully produced donor-derived tiger puffer offspring presenting the same body surface dot pattern, number of dorsal fin rays, and DNA fingerprint as those of the donor tiger puffer, suggesting that the recipient grass puffer produced functional eggs and sperm derived from the donor tiger puffer. Although fine tunings are still needed to improve efficiencies, surrogate grass puffer are expected to accelerate the breeding process of tiger puffer because of their short generation time and small body size.

A new species of Amaralia Fowler (Siluriformes: Aspredinidae) from the Paraná-Paraguay River Basin.

A new species of the banjo catfish genus Amaralia is described from the Paraná-Paraguay River Basin in central-western Brazil, Paraguay and northern Argentina. Amaralia oviraptor is distinguished from its single and allopatric congener, Amaralia hypsiura, by the greater number of dorsal-fin rays (3 vs. 2); by the absence of lateral contact between middle and posterior nuchal plates (vs. middle and posterior nuchal plates contacting each other laterally); and by a longer cleithral process (17.4-19.5 % of SL, mean 18.2 % vs. 14.0-17.2 % of SL, mean=15.5 %). Comments on the peculiar oophagic diet of Amaralia and an extended diagnosis of the genus are provided.

Description of Hylopanchax paucisquamatus (Cyprinodontiformes: Poeciliidae), a new lampeye species from the Odzala-Kokoua National Park, Republic of Congo

A new deep-bodied Hylopanchax species is described from the northwestern Congo basin. Hylopanchax paucisquamatus, new species, was collected in the Odzala-Kokoua National Park in the Likouala River drainage of the Republic of Congo. It differs from its congeners, including the deep-bodied H. leki and H. ndeko, by a unique combination of morphological characters, including low number of mid-longitudinal and transverse scales, number of dorsal-fin rays, and position of dorsal-fin origin in relation to anal-fin. It is the only deep-bodied species currently known outside the Kasaï River drainage.

Hybrid salmonids: ploidy effect on skeletal meristic characteristics and sea lice infection susceptibility

Summary This study examined how triploidization and species hybridization affects skeletal related meristic characteristics in salmonids with the goal of understanding the maternal and paternal contribution. The study also investigated the hybrid sea louse infection rate in hybrid salmonids. In order to do so, a number of vertebrae, scales along the lateral line, and dorsal fin rays were measured in diploid and triploid Atlantic salmon, Arctic char, and Atlantic salmon (female) X Arctic char (male) hybrids. The success of triploidization was 100%, and some spontaneous triploid individuals (~15%) were found among the hybrids. In general, hybrids displayed intermediate counts for all three characteristics with salmon displaying the highest number of dorsal fin rays, and char displaying the highest number of scales and vertebrae. The effect of triploidization was always strongest among the hybrids. However, the direction of the effect differed between structures in the hybrid; triploidization increased the number of vertebrae and reduced the number of fin rays towards the level observed in diploid char, and reduced the number of scales towards the level observed in diploid salmon. We conducted a second experiment whereby diploid Atlantic salmon and Atlantic salmon (female) X Arctic char (male) hybrids were exposed to an experimental challenge with the parasitic salmon louse (Lepeophtheirus salmonis). There was no difference in the sea-lice infection level between Atlantic salmon and the hybrids. This study shows that the present model with diploid and triploid Atlantic salmon (female) X Arctic char (male) hybrids may be a useful tool for the study of which traits are maternally and paternally inherited in salmonids. The understanding of morphological development with regard to meristic traits could be advantageous for both hybrid and triploid fish domestication.

Betta hendra - a new species of fighting fish (Teleostei: Osphronemidae) from Kalimantan Tengah (Borneo, Indonesia)

Betta hendra spec. nov. is described from Kalimantan Tengah, Borneo, Indonesia. It is a bubble-nesting fighting fish of the B. coccina species group. The new species differs from the other members of the group by a bright greenish iridescent colour on the flanks and unpaired fins. It is distinguished from its geographical neighbour species B. uberis by a lower number of dorsal-fin rays (10–12 versus 14–17).

A New Genus of Glyptosternine Catfish (Siluriformes: Sisoridae) with Descriptions of Two New Species from Yunnan, China

Creteuchiloglanis, new genus, is established for three species previously placed in Pareuchiloglanis (P. gongshanensis, P. kamengensis, and P. macropterus) and two new species described herein. Creteuchiloglanis is distributed in the upper Mekong River (Lancang-Jiang) basin west to the Brahmaputra River basin and is distinguished from Pareuchiloglanis by a unique combination of characteristics involving the form of the connection of the lower lip to the maxillary barbel, premaxillary tooth patches, and the morphology of the dilator, operculi, sternohyoideus, and adductor pelvicalis superficialis muscles. Creteuchiloglanis brachypterus, new species, from the upper Irrawaddy River basin in China, is diagnosed by a unique combination of characteristics involving pectoral- and pelvic-fin length, caudal-peduncle length and depth, pelvic-fin position, caudal-fin length, eye size, body and head depth, and coloration. Creteuchiloglanis longipectoralis, new species, from the upper Mekong River (Lancang-Jiang) basin, is diagnosed by a unique combination of characteristics involving pectoral- and pelvic-fin length, caudal-peduncle length and depth, pelvic-fin position, body and head depth, post-adipose fin distance, number of dorsal-fin rays, and coloration. New diagnoses are provided for previously described congeners C. gongshanensis from the upper Salween River (Nu-Jiang) basin, C. kamengensis from the Brahmaputra basin, and C. macropterus from the upper Irrawaddy River and upper Salween (Nu-Jiang) basins.

Larvae and juveniles of Leptoderma lubricum and L. retropinnum (Argentiformes: Alepocephalidae) collected from Suruga Bay, Japan

Larvae and juveniles of the alepocephalid fishes, Leptoderma lubricum [26.9–69.0 mm in standard length (SL)] and Leptoderma retropinnum (21.1–67.2 mm SL), collected within 1–8 m of the seafloor in Suruga Bay, southern Japan, are described. They can be easily distinguished from each other by the following adult-like characters: membrane morphology between the vertical fin rays and procurrent caudal-fin rays (separated in L. lubricum vs. continuous in L. retropinnum), numbers of dorsal-fin rays (34–40 vs. 45–52) and anal-fin rays (50–57 vs. 65–72), and caudal peduncle length (11.7–13.4% SL vs. 4.5–5.9% SL), in addition to several other body proportional differences. Unique characters in the larval stages of Leptoderma include a translucent occipital region, horizontally elongated eye, and head below the upper margin of the orbit and abdominal cavity densely covered by melanophores, ontogeny being characterized by the acquisition of general adult characters to the postflexion stage, indistinct transformation, and the retention of few larval characters until almost the end of the juvenile stage, as in other known alepocephalids. In addition to the near-bottom larval and juvenile collections of both species, the occurrences of benthic or near-bottom taxa, including Harpacticoida, in their gut contents confirmed the early life history dependence of the former on the near-bottom.

A new species of Simpsonichthys (Cyprinodontiformes: Rivulidae) from the rio São Francisco basin, northeastern Brazil

Simpsonichtys lopesi n. sp. is described from a temporary pool located in the São Francisco river basin. This species is distinguished from remaining species, except S. adornatus, by the large number of dorsal fin rays, which makes possible a large dorsal fin base length that begins well anterior to the middle of the body, before the vertical line through the pelvic fin. This species differs from S. adornatus by the color pattern of the anal fin, which may have yellow stripes or light dots (vs. small light points), and also by the lower number of dorsal fin rays.