Barbel Length Research Articles

New species of Batrochoglanis Gill (Siluriformes: Pseudopimelodidae) from the Capim River basin, State of Pará, Brazil

Batrochoglanis labrosus new species, is described from the Capim River Basin, State of Pará, Brazil. The new species differs from congeners by the stout, inferior mandible, hypertrophied lips on the lateral of the mouth, a broad dark brown band extending dorsoventrally from the beginning of the trunk to the posterior third of the adipose fin followed by a second dark brown band on the caudal peduncle, dark brown pelvic fin, and caudal fin hyaline with a concentration of dark brown spots on the posterior margin, sometimes forming an irregular band. The morphometric variables of B. labrosus are similar in B. villosus and B. castaneus, forming a B. villosus species group. The B. villosus group is distinct from other group formed by B. acanthochiroides and B. transmontanus in the third axis of the Principal Components Analysis. The variables with higher positive loadings in the B. villosus group, representing larger measurements, were adipose-fin base length, eye diameter, maxillary barbel length, head depth, and mouth width; the higher negative loadings representing shorter measurements were pelvic fin to anal fin distance and pectoral-fin spine length. The species is known only from the Capim River basin, where it is possibly endemic.

Balitora anlongensis, the first cavefish species of the genus Balitora (Teleostei, Balitoridae) from Guizhou Province, southwest China

This work describes a new species, Balitora anlongensissp. nov., collected from a cave at Xinglong Town, Anlong County, Guzihou, China. Phylogenetic trees reconstructed based on two mitochondrial and three nuclear genes show that the new species represents an independent evolutionary lineage with large genetic differences, 7.1%–12.0% in mitochondrial gene cytochrome b and 9.2%–12.1% in cytochrome oxidase subunit 1, from congeners. Morphologically, the new species can be distinguished from the 18 species currently assigned to the genus Balitora by a combination of characters, most clearly by having two pairs of maxillary barbels; 8½ branched dorsal-fin rays; 5½ branched anal-fin rays; pectoral fin not reaching pelvic fin origin; dorsal-fin origin in front of pelvic fin origin; eye small (eye diameter approximately equal to outer maxillary barbel length); and fins lacking pigment in live fish. The new species represents the first record of Balitora inhabiting caves in China and increases the number of species in the genus Balitora in its present concept from 18 to 19. The study suggests that more evidence is needed to further clarify the taxonomic composition of the genus Balitora.

Comparative and morphological review of plunderfishes of the genus Artedidraco (Artedidraconidae, Notothenioidiei)

The external morphology and axial skeleton of 5 species of Antarctic plunderfishes of the genus Artedidraco Lönnberg, 1905 were studied using materials from the collection of ZIN. Plastic (26) and meristic (14) characters were analyzed; a morphological characteristics of the species was prepared. The results of the study partially con firm the previously revealed differences between the species of the genus, but some diagnostic characters of plunderfishes are found for the first time: the number of branched rays of the caudal fin, height of the head, length of the chin barbel and height of the second dorsal fin, predorsal, preanal and prebranchial distances, number of vertebrae in different parts of the spine. Assumptions are made about the functional role of characters, according to which the differences between the species associated with the diet and habitat of these fish are established. Two groups of Artedidraco species were found: “skottsbergi” (A. skottsbergi Lönnberg, 1905, A. loennbergi Roule, 1913) and “shackletoni” (A. shackletoni Waite, 1911, A. glareobarbatus Eastman et Eakin, 1999). Species of A. mirus Lönnberg, 1905 and A. orianae Regan, 1914 were not assigned to any group, since during the work a sufficient number of their similarities was not found. An identification key for species of the genus was compiled.

Ecomorphology of a predatory deep-sea fish family: does trophic specialization drive hyperspeciation?

Two of the main drivers of speciation among aquatic vertebrates are physical isolation (e.g., lakes and streams) and micro-niche availability (e.g., tropical reefs). In both regards, the mesopelagic domain of the open ocean, Earth’s second largest cumulative ecosystem (behind only the bathypelagic domain), would seem retardant. Ocean circulation makes isolation rare on both contemporary and geological time/space scales, and the lack of substrate precludes stable micro-niches. Paradoxically, some pelagic taxa demonstrate much higher-than-expected species richness on regional scales. A prime example is the dragonfish family Stomiidae, the most speciose family of mesopelagic fishes, owing largely to the subfamily Melanostomiinae (scaleless black dragonfishes), which contributes 222 of the 320 described species. Within genera, species are differentiated almost solely by form of the jugular-positioned, bioluminescent barbel, a structure putatively linked to feeding (via prey luring). The relationship between diversity (both systematic and morphological) and diet within the Melanostomiinae has not been previously examined, primarily due to sample size limitation. Herein, the diet and morphology of 16 species of melanostomiine dragonfishes from the Gulf of Mexico were examined to ascertain whether the diversification in this fish clade is based on prey specialization, as is the case with many other speciose fish families (e.g., Cichlidae). Gut content analysis revealed a rather small spectrum of prey taxa across a wide spectrum of predators, with most species exhibiting piscivory centered on the most regionally abundant lanternfishes (Myctophidae). Lesser numbers of species preyed upon bristlemouths (Gonostomatidae), oceanic basslets (Howellidae), bigscales (Melamphaidae), and other dragonfishes, while three species selected for cephalopod prey. No dragonfish species consumed macrocrustaceans (e.g., decapod shrimps), despite their numerical prevalence as potential prey. Regarding functional morphology, dissimilarity was driven mostly by barbel length, vertical oral gape, and horizontal maxillary oral gape. There were no robust morphological-dietary relationships amongst melanostomiines, with dietary diversity much lower than morphological diversity. These results suggest that other factors, perhaps conspecific recognition and/or sexual selection related to spawning, may be primary drivers of hyperspeciation in the micro-habitat-poor pelagic environment.

Taxonomic and Otolith Shape Parameters of Nine Sympatric Catfishes Commercially Harvested in Pakistan

Abstract Accurate reorganization of harvested species is essential for appropriate fisheries monitoring but often unnoticed. In this study, an attempt was made to provide an accurate species description based on fish taxonomy and otolith shape parameters of nine sea catfishes living in Pakistan. The lapillus, the largest otolith of catfishes, includes the position of the umbo, the structure of the anterior mesial projection (amp), the incisura linea basalis (ilb) and sulcus lapilli marks (slm) in nine ariid catfishes were evaluated. Discriminant function analysis was performed using twenty-two morphometric parameters showed significant variations between the length of the maxillary barbel, adipose length and preorbital length, which were highlighted as basic discriminating characters. Species without barbells, such as Batrachocephalus mino and Osteogeneiosus militaris, were found to be distant. The taxonomic characters of the genera Netuma and Plicofollis overlapped due to a short adipose fin length. Nevertheless, species Arius arius, Sciades sona and Nemapterxy caelatus differed in a moderate adipose fin length. The preorbital length of Netuma bilineata has a short and rounded snout, while N. thalassina has a long and pointed snout, which is a distinguishing characteristic of both species. The coincident use of fish taxonomy and otolith shape parameters is an effective tool for catfish identification could be helpful in appropriate fisheries sampling programs and management in Pakistan whenever implemented.

Exostoma dhritiae, a new sisorid catfish (Teleostei: Sisoridae) from the Brahmaputra River drainage, Arunachal Pradesh, India

A new species of sisorid catfish of the genusExostomais described from the Siang River in Arunachal Pradesh, northeastern India. The new species,Exostoma dhritiae, can be distinguished from congeners by the condition of the posterior extremity of the adipose-fin base, the degree of tuberculation on the dorsal surface of the head, and the shape of striae on the anterolateral surface of lips. Further, it is distinguished by the morphometric data for the body depth at the anus, maxillary barbel length, adipose fin base length, caudal peduncle length, caudal peduncle depth and the number of branched pectoral-fin rays. It is the twentieth reported species of Exostoma.

Morphology and Anatomy of Endemic Fish Leptobarbus melanopterus (Cyprinidae) in Danau Sentarum National Park Kapuas Hulu Regency

One of the endemic freshwater fishes in Danau Sentarum National Park (DSNP) is Leptobarbus melanopterus which has high economic value for both commercial and collection purpose. However, the overfishing of L. melanopterus running over decades with harmful catch tools is worried could contribute to the population decline in the future. At the same time, this species has never been cultured and fishermen catch directly in the habitat on a daily basis. This research was aimed to identify the morphological and anatomical characters of L. melanopterus. All samples were collected from three different sites in DSNP and measured its morphological and anatomical sizes manually. The results showed that the length of mandibula barbel was the distinguishing character between females and males, with loading score of 0.81. Most meristic variables showed no difference between two sexes. In terms of anatomical measurements, L. melanopterus females had larger gill sizes than males, including gill raker, gill arch and fill filament. Our findings signify the thorough morphological and anatomical sizes of L. melanopterus which are important in identifying fish stock, growth pattern and sexual dimorphism for future culture management.

Revision of the Tubenose Poacher Genus Pallasina Cramer (Perciformes: Cottoidei: Agonidae)

Species of the tubenose poacher genus Pallasina are assessed following examination of over 450 specimens from throughout the Pacific Rim, from the coast of California to the Chukchi Sea and Sea of Japan. The results presented here, including both morphological and mitochondrial DNA datasets, indicate that three species of Pallasina occur in the North Pacific and surrounding seas. Pallasina aix is found in the eastern North Pacific from California to southeast Alaska and in the Salish Sea. It has the shortest barbel of the three species and a unique haplotype in the mitochondrial COI region. Pallasina barbata is the most widespread species, ranging from the Gulf of Alaska to the Chukchi Sea and west to northern Japan. It is distinguished by having a moderate barbel length and can be separated from the other two species using a variety of meristic characters. Pallasina eryngia is found only in the central and northern Japanese Archipelago, and it is a relatively deep-water species. It is distinguished by having a long barbel, as well as relatively high counts of vertebrae and dermal plates. This study presents redescriptions of all three species and a key to their identification.

Stock structure delineation of an endangered mahseer, Tor putitora (Teleostei: Cyprinidae) from two Indian rivers by morphological and meristic attributes

An understanding of the stock is a basic requirement for the management of the fishery resources. The endangered mahseer, Tor putitora (Hamilton, 1822) is a commercially important fish distributed extensively in the foothills of Himalayas. Box plots and multivariate statistical tools like Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) were used to delineate the stocks of T. putitora from two Indian rivers, Yamuna and Satluj using 6 meristic and 24 morphometric characteristics. A comparison of the morphometric and meristic characters using box plots revealed variations in eye diameter (ED), length of rostral barbel (LRB), standard length (SL), pre-anal distance (PAD), distance between pectoral and pelvic fin (DPP), distance between pelvic and anal fin (DPA), length of dorsal fin (LDF), length of pectoral fin (LpecF), length of pelvic fin (LpecF) and length of caudal fin (LCF) for distinguishing populations from these two rivers. Upon PCA, the first three principal components accounted for 69.66% of total variance in head parameters whereas for total length, the first 5 principal components accounted for 73.23% of total variance. For meristic characters, the first two PCs explained 75.65% of the total variance. The step-wise DFA retained only one function for morphometric as well as meristic characters explaining 100% of the variance. The Wilks’ lambda tests for morphometric and meristic data indicated differences between the populations of T. putitora from both the rivers.

‘Henicorhynchus’ thaitui, a new species of cavefish from Central Vietnam (Teleostei, Cyprinidae)

‘Henicorhynchus’thaituisp. nov. is described from a subterranean stream in a karst cave in Phong Nha Ke Bang National Park, Quang Binh Province, Central Vietnam. It differs from all congeners in having a pale pink body in life, smaller eyes with diameter less than the maxillary barbel length, and two pairs of barbels, the maxillary barbel being much longer than the rostral barbel.

Otolith Shape and Characteristics as a Morphological Approach to the Stock Identification in Barbus tauricus (Cyprinidae)

This study is aimed to discriminate Barbus tauricus stocks using otolith shape indices and morphometrics. B. tauricus samples were obtained from some inland waters of Black Sea basin (Streams Akcay, Engiz, Terme, Karadere and Degirmenagzi), and also Luciobarbus sp. samples from Sakarya River were used as an outgroup. Utricular and lagenar otoliths were removed by making left and right distictions. Otolith width, length, perimeter and area were determined by Imaging Software. Power model was applied to estimate the relationships between the otolith measurements and total length. Form Factor, Circularity, Roundness, Rectangularity, Aspect Ratio and Ellipticity were used for otolith shape analyses. A standardized model was used to remove size effect on otolith measurement. Discriminant function analysis were performed to detect differences in otolith shape variations. The discriminant function analysis performed for otolith shape indices and measurements explains the intraspecific variability among localities. According to discriminant function analysis, 75.3% of B. tauricus stocks were correctly classified. The results of this study provide the first comprehensive data regarding the otolith shape analyses and relationship between the otolith morphometrics with total length of Crimean barbel.

Morphometric characteristics of diploid and triploid Far Eastern catfish, <i>Silurus asotus</i>

This study identified the differences in the morphometric characteristics of the truss and classical dimensions between diploid and triploid Far Eastern catfish, Silurus asotus, and provided methods for sorting diploid and triploid Far Eastern catfish based on morphometric observations. The significant variables were the direct distance between the anterior edge of the lower lip and the anterior insertion of the dorsal fin (DALAD), the horizontal distance between the anterior edge of the lower lip and the anterior insertion of the ventral fin (HALAV), the direct distance between the anterior edge of the upper lip and the first nostril (DAUF), the direct distance between the anterior edge of the upper lip and the second nostril (DAUS), the interorbital width (IW), and the mandible barbel length (ManBL). The more significant variables were HALAV, DALAD, DAUF, IW, and DAUS. The most useful combination of variables for separating the two groups was DALAD, IW, and DAUF, which correctly classified 85% of the catfish as triploid or diploid, and that percentage was the maximum degree of value possible (p<0.05). Triploid Far Eastern catfish had a high rate of growth in the head region and body depth during the first year after hatching. Triploid Far Eastern catfish had smaller heads and shorter mandible barbels than diploid Far Eastern catfish.

Barilius torsai (Teleostei: Cypriniformes: Cyprinidae), a new freshwater fish from the Brahmaputra drainage, India

Barilius torsai is described from the Torsa, a tributary of Brahmaputra River system in West Bengal, India. The new species is distinguished from all its congeners by the presence of a complete lateral line with 52–53 scales, 29 pre-dorsal scales, pectoral fin notched, two well-developed pairs of barbels (rostral and maxillary), length of rostral barbel slightly larger than maxillary, which reaches the orbit. Tubercles on snout and lower jaw absent, 9–11 blue vertical bars along the body, dorsal fin hyaline with dark pigment concentrated along lower two-third of the dorsal-fin rays.

Biometric studies of Ailia coila (Hamilton, 1822) from river Brahmaputra, Assam, India

For the study of length-weight relationship, morphometric and meristic characters, a total of 711 specimens (196 male and 515 female) of the Gangetic ailia, Ailia coila (Hamilton, 1822) were collected from Uzanbazar and Dhubri landing centres of river Brahmaputra, Assam during September 2013 to April 2014. The length and weight of males ranged from 66 to 154 mm and 1.218 to 20.5309 grespectively and that of females ranged from 66 to 161 mm and 1.4344 to18.2907 g respectively. The length-weight relationship was established as W = 0.002773 L 3.189306 and W = 0.005794 2.86234 for male and female, respectively. The analysis of covariance showed significant difference in ‘b’ values between sexes and student ‘t’ test indicated positive allometric growth for male and isometric growth for female. The morphometric characters were compared; showed maximum co-efficient of correlation (r) in standard and pre-dorsal length (0.98) while lowest was observed in mandibular barbel length (0.69) against the total length. Based on the study of meristic traits, the fin formula can be written as B6, P12-15, V5-6, C14-18, A61-75, GR17-24. The minor variations in meristic and morphometric characters could be attributed to genetic components and difference in geographical and environmental parameters like temperature and food availability. The study will helpful in identification of stock and stock-specific management strategies of this species in river Brahmaputra, Assam.

Sexual dimorphism in morphometric characters of Mystus singaringan from Klawing River in Central Java, Indonesia: Strategic instruction for conservation development

Abstract. Pramono TB, Arfiati D, Widodo MS, Yanuhar U. 2019. Sexual dimorphism in morphometric characters of Mystus singaringan from Klawing River in Central Java, Indonesia: Strategic instruction for conservation development. Biodiversitas 20: 1133-1139. This study aims to determine the sexual dimorphism of Mystus singaringan (Senggaringan fish) based on morphometric characters. The measurement of 24 morphometric characters in 30 M. singaringan from Klawing River was carried out using a digital caliper (0.01 mm). Morphometric data of M. singaringan analyzed using t-test have showed significant difference in 12 morphometric characters between sexes, such as standard length, head height, distance of the tip of the muzzle to eyes, distance of the tip of the muzzle to adipose fin, height of dorsal fin, height of pectoral fin, basic length of adipose fin, height of adipose fin, maximum height, length of first nasal barbel, length of first mandibular barbel, and length of second mandibular barbel. Analysis of growth of morphometric characters shows that there is a linear relationship between all morphometric characters and total length. The type of growth of all morphometric characters in both male and female M. singaringan is negative allometric.

Description of A New Species of the Gudgeon Genus Microphysogobio Mori 1934 (Cypriniformes: Cyprinidae) from Guangdong Province, Southern China.

Shih-Pin Huang, I-Shiung Chen, Yahui Zhao, and Kwang-Tsao Shao (2018) Microphysogobio luhensis n. sp., a new cyprinid species, is described from the Rongjiang River in eastern Guangdong Province, China. Morphological characters and molecular evidence based on mitochondrial DNA Cytochrome b (Cyt b) and Cytochrome oxidase subunit I (COI) sequences were used to compare this new species with other related species from mainland China, Vietnam and Taiwan. The present molecular evidences revealed that this new species is closely related to M. kachekensis and M. yunnanensis. However, these three species can be well distinguished based on the number of small pearl-like papillae on their inside papillae, lip papillae shape, barbel length, barbel width and color pattern. Furthermore, the morphometric comparison between M. kachekensis and the poorly known species M. yunnanensis is also discussed in this study for the first time. In addition, a diagnostic key to all 14 valid species of Microphysogobio from southern mainland China, Hainan Island and Taiwan is also provided.

Molecular and morphological evidences resolve taxonomic ambiguity between Systomus sarana sarana (Hamilton, 1822) and S. sarana subnasutus (Valenciennes) and suggest elevating them into distinct species

Taxonomic ambiguity exists in genus Systomus and recently many new species were described under this genus. Systomus sarana subnasutus is considered a valid subspecies of S. sarana sarana although revisions have been done by some researchers. We employed a combination of morpho-meristics and molecular tools (Cytochrome c oxidase I, 16S and Cytochrome b genes of mitochondrial genome) to resolve the two species. Three morpho-meristic characters, head length/maxillary barbel length (HL/MxBL), Lateral Line Scales (LLSs) as well as two truss-based characters, had discernible variation between the two taxa. The sequence analysis (2353 nucleotides) depicted a separate clad of S. sarana subnasutus with high bootstrap support. The findings from combined use of morphology, meristics and mitogenes were concordant. The corroborative results suggest the possibility of two different species. The results suggest to adopt suitable management measures, accordingly.

A New Glyptosternine Catfish from Northern Myanmar (Teleostei: Siluriformes: Sisoridae)

A new species of sisorid catfish in the genus Exostoma is described from the upper Irrawaddy River drainage in northern Myanmar. The new species can be distinguished from congeners by the condition of the posterior extremity of the adipose-fin base, the degree of tuberculation in the preorbital area, as well as morphometric data for the nasal barbel length, snout length, interorbital distance, adipose fin-base length, body depth at anus, caudal-peduncle length, and caudal-peduncle depth. The taxonomic status of congeners in the Irrawaddy River drainage is also discussed, and E. chaudhurii is revalidated as a distinct species.

Comparative study of morphometric characters of diploid and triploid juvenile catfish, Clarias gariepinus

The study was conducted to compare morphometric variables of diploid and triploid Clarias gariepinus. A total of 17 morphometric characters were measured. Five length classes of 10 samples each for each strain was chosen thus: Class1 (7.5cm - 10.4cm), Class2 (10.5cm - 13.4cm), Class3 (13.5cm – 16.4cm) Class4 (16.5 cm - 19.4cm), and Class5 (19.5cm - 22.4cm). Data collected were subjected to statistical analysis for significance at 5% probability level using descriptive statistics. Results revealed that measurements showed linear correlation between fish length and size in both strains. When the diploid and triploid groups were compared it was observed that body characters (85.6% of total characters) were higher in triploid than diploid fishes. However, head characters were observed to be higher in diploid than triploid. For instance, in Class1, diploid fish had higher values for barbel length (diploid 3.08cm; triploid 3.0cm), pre-pectoral fin length (diploid 2.05cm; triploid 1.99cm) and pre-maxillary width (diploid 0.97cm; triploid 0.91). A similar trend was observed in all other length classes. There were no significant differences (p > 0.05) in morphometric characters relating to body measurements. This considered the triploid fish to be closely related to the diploid group which can be confirmed by the study of genetic characters. Key Words: Morphometric characters, Diploid, Triploid, Juveniles, Clarias gariepinus

Landmark-based Morphometric and Meristic Variations of Endangered Mrigal Carp, Cirrhinus cirrhosus (Bloch 1795), from Wild and Hatchery Stocks

Wild stocks of endangered mrigal carp, Cirrhinus cirrhosus (Bloch 1795), continues to decline rapidly in the Indo-Ganges river basin. With an objective to evaluate its population status, landmark-based morphometric and meristic variations among three different stocks viz., hatchery (Jessore), baor (Gopalganj) and river (Faridpur) in Bangladesh were studied. Significant differences were observed in 10 of the 15 morphometric measurements viz., head length, standard length, fork length, length of base of spinous, pre-orbital length, eye length, post-orbital length, length of upper jaw, height of pelvic fin and barbel length, two of the 8 meristic counts viz., scales above the lateral line and pectoral fin rays and 10 of the 22 truss network measurements viz., 1 to 10, 2 to 3, 2 to 8, 2 to 9, 2 to 10, 3 to 4, 3 to 8, 4 to 5, 4 to 7 and 9 to 10 among the stocks. For morphometric and landmark measurements, the 1st discriminant function (DF) accounted for 58.1% and the 2nd DF accounted for 41.9% of the among-group variability. In discriminant space, the river stock was isolated from the other two stocks. On the other hand, baor and hatchery stocks formed a very compact cluster. A dendrogram based on the hierarchical cluster analysis using morphometric and truss distance data placed the hatchery and baor in one cluster and the river in another cluster and the distance between the river and hatchery populations was the highest. Morphological differences among stocks are expected, because of their geographical isolation and their origin from different ancestors. The baseline information derived from the present study would be useful for genetic studies and in the assessment of environmental impacts on C. cirrhosus populations in Bangladesh.