Morphological variation of the endemic sisorid fish, Glyptothorax platypogon (Teleostei: Sisoridae) from Java, Indonesia: conventional and truss-based morphometrics

Morphological variations of the Asian sheat catfish, Wallago attu (Bloch and Schneider, 1801) sampled from the rivers Gomti, Ganga, Yamuna at Lucknow, Kanpur and Agra districts in Northern India, river Hooghly at Kolkata in Eastern India and river Pampa at Kerala in Southern India were analyzed in the present study. Images of 261 specimens of W. attu were taken without harming the fish to evaluate the morphometric variation using 8 digitized homologous landmarks for truss analysis and geometric morphometrics. Size corrected morphometric variables were analyzed using analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), principal component analysis (PCA) and discriminant function analysis (DFA). Coefficients of all PCs were positively and negatively correlated to 31 significant (p 0.001) truss measurements due to variations in size and shape. Morphometric measurements lying in the head region such as head length (HL), eye diameter (ED), inter-orbital length (IOL) and snout length (SNL) contributed most to differentiate the populations in truss analysis. The ED, HL, SNL and IOL of Yamuna fish was significantly (p 0.001) smaller than the other fish populations. This could be attributed to the heavy pollution load in the Yamuna River and differences in the feeding regimes of fish. PCs and relative warps depicted differences in geometric analysis because of body shape variations among different river populations. The scatter plot in DFA revealed the presence of three distant and different phenotypic groups of W. attu among five wild river populations of fish with 70.5 and 83.9% of correct classification of fish into their original groups in truss and geometric analysis respectively. A single homogenous stock of fish was found to be in the rivers Gomti, Ganga and Hooghly because of a high level of intermixing (maximum misclassification) among the three river populations, whereas Yamuna and Pampa populations were two non-overlapping isolated groups due to negligible intermixing. These variations in the present study might be the effect of geographical isolation and river fragmentation due to the change in habitat that restricts fish movements. This is the first report on the morphometric assessment of W. attu that provides base line data for further confirmatory stock studies that would be useful for conservation and sustainable management of this vulnerable fish.

A research study on morphometrics of Kalophrynus palmatissimus (commonly known as Lowland Grainy Frog) at Ayer Hitam Forest Reserve (AHFR), Selangor and Pasoh Forest Reserve (PFR), Negeri Sembilan was carried out from 12 November 2016 to 13 September 2017. The study was to examine data on the morphometric traits of K. palmatissimus at the two forest reserves. 15 morphometric traits of K. palmatissimus that were taken by using vernier calipers. Frog surveys were done by using 15 and 18 nocturnal 400 m transect lines with an interval distance of 20 m at AHFR and PFR, respectively. The GPS coordinates for all frog samples were recorded to ensure the precise geographic location. In addition, five climatic data were recorded. The results showed that most morphometric traits in AHFR (n = 34) and PFR (n = 31) were positively correlated with each other. On the other hand, climatic factor, which was soil pH, had a significant positive influence on most of the morphometric traits (p < .01), except for tympanum diameter and upper eyelid width (p ≥ .05). Meanwhile, the temperature had a significantly negative influence on all morphometric traits (p < .01). General linear model (GLM) analysis showed that snout‐vent length (SVL) influenced most morphometric traits (F ≤ 80.86, p < .01), except for hand length (HAL: F = 0.299, p > .05). Later, it was found that the snout‐vent length of K. palmatissimus at AHFR was slightly larger than at PFR (AHFR: μ = 37.00 mm, SE = 1.16 c.f. PFR: μ = 30.29 mm, SE = 1.07). It showed that there were variations in morphometric traits of K. palmatissimus at AHFR and PFR. From PCA analysis, morphometric traits are grouped into two components for AHFR and PFR, respectively. In AHFR, head length, eye diameter, head width, internarial distance, interorbital distance, forearm length, tibia length, foot length, and thigh length were strongly correlated, while snout length and eye‐nostril distance were strongly correlated. In PFR, eye diameter, head width, internarial distance, interorbital distance, foot length, and thigh length were strongly correlated, though snout length and eye‐nostril distance were strongly correlated, hence, suggested that all morphometric traits grow simultaneously in K. palmatissimus with eye‐nostril distance (EN), and snout length (SL) growing almost simultaneously at AHFR (r = .91) and PFR (r = .97). There is still a lack of available information regarding the distribution and morphometric studies of K. palmatissimus in Malaysia, especially at AHFR and PFR. This study showed 15 different morphometric traits of K. palmatisssimus between AHFR and PFR, with K. palmatissimus at AHFR were found to be slightly larger than at PFR.

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.

A study on morphometric characters of Indian Major Carp- Labeo rohita was conducted and the fish were collected from the fish markets of Lucknow. Labeo rohita, commonly known as rohu is a species of fish that belongs to the family Cyprinidae and the order Cypriniformes. It is a warm water teleost and primarily feeds as a column feeder herbivore. Ten morphometric characters, length-weight relationship of Labeo rohita were studied. The morphometric measurements like total length, standard length, head length, snout length, body depth, eye diameter, pre-dorsal length, pre-pelvic length, pre-pectoral length and caudal length and body weight were recorded. The descriptive statistical parameters and correlation coefficient were analysed with independent and dependent variables. The morphometric character showed gradual increase in the body length and weight. A positive correlation has been observed between total length and other morphometric characters like standard length, head length, snout length, body depth, eye diameter, pre-dorsal length, pre-pectoral length, pre-pelvic length, caudal length. The value of ‘b’ of the length-weight equations is 3.949 which suggest that fish possess positive allometric growth.

The morphometric analysis was carried out in indigenous cyprinid food fish, Schizothorax labiatus (a species of snow trout) collected from Vishav stream, a perennial cold water stream of Kashmir valley, India, wherein various morphometric characters viz., Total Length (TL), Standard Length (SL), Fork Length (FL), Pre-dorsal Length (PDL), Pre-pectoral Length (PPL), Pre-pelvic Length (PPeL), Pre-anal Length (PAL), Anal Fin Length (AL), Head Length (HL), Height of Dorsal Fin (HOD), Snout Length (SnL), Body Depth (BD), Eye Diameter (ED), Inter Orbital Length (IOL), Caudal Fin Length (CL) and Caudal Depth (CD) of 104 fish specimens were measured, correlated and analysed. The morphometric data was calculated in the percentage of total length except SnL, ED and IOL which were calculated in the percentage of HL. The result revealed that the correlation coefficient ranged from 0.770 to 0.995 in proportion to TL and 0.706 to 0.859 in proportion to HL which indicates that all the morphometric characters are highly correlated. All the correlations were significant at the level of p<0.01. During the investigation, the results revealed that in the % of TL, 8 characters were found to be genetically controlled 4 characters as intermediate and none character as environmentally controlled one. In the % of HL, 1 character was found to be included in intermediate character, 2 characters in environmentally controlled characters and none in purely genetically controlled one. As revealed by the regression analysis of different morphometric characters in proportion to TL, the maximum growth was obtained for FL (b = 0.9664) and the minimum growth was obtained for AL (b = 0.0655) and in proportion to HL, the maximum growth was obtained for IOL (b = 0.4689) and the minimum growth was obtained for ED (b = 0.0852).

In the present study, some meristic and morphometric characteristics of 66 Capoeta trutta (Heckel, 1843) fish samples collected from Murat River (Palu-Elazığ) were examined. The samples were immediately preserved with ice and fixed with 5% formaldehid on arrival in the laboratory. Metric measurements were carried out with 0.01 mm sensitive calipers. Meristic characters were counted as number of the dorsal fin rays, number of the anal fin rays, number of the pelvic fin rays, number of the pectoral fin rays, number of scales on the lateral line and number of the pharyngeal teeth. The morphometric characters were measured as total length, fork length, standard length, predorsal length, postdorsal length, caudal peduncle length, body width, body height, snout length, head length, head width, eye diameter, mouth width, intertorbital length, distance between pelvic fin and anal fin, distance between pelvic fin and pectoral fin. Morphometric measurements as total length percentage and total length regression models and determination coefficients (r2) were calculated. Generally, a significant, high, positive correlation was found between total length and morphometric measurements (r2= 0.70-0.92, p&lt;0.01).

Significant variations in the multivariate morphometric analysis were observed in the sub-populations of freshwater murrel, Channa punctatus from two habitats characterized by different environmental conditions. A linear relationship was noted between different body measurements and total length of the fish in both the environments. The 14 morphometric parameters found to be significant (p < 0.05) in univariate (one way ANOVA) analysis were further subjected to multivariate analysis using principal component and discriminant function analysis. Principal component analysis indicated shape variation and accounted for 76 % of the total variance. In discriminant function analysis of the significantly different morphometric parameters, 96.9 % of cross-validated grouped cases were correctly classified and the sub-populations were discriminated. Parameters like dorsal fin length, snout length, inter-orbital length, pre-anal length, head length, pre-dorsal length and pre pectoral length were mainly responsible for variations and discrimination between the sub-populations in the discriminant function analysis. The fish from the two environments also deviated from the so called cube law which indicated the different growth rate in length-weight relationship study. Significant divergence in morphometric analysis revealed that intraspecific variations existed between the two sub-populations of C. punctatus. Therefore, these findings indicate the presence of two different stocks of C. punctatus.

Abstract. Fauziyah, Mustopa AZ, Fatimah, Purwiyanto AIS, Rozirwan, Agustriani F, Putri WAE. 2021. Morphometric variation of the horseshoe crab Tachypleus gigas (Xiphosura: Limulidae) from the Banyuasin estuarine of South Sumatra, Indonesia. Biodiversitas 22: 5061-5070. Morphological studies are essential for fish resource management, ecology, conservation, and stock assessment. This research was conducted to characterize the morphological variation of the coastal horseshoe crab (Tachypleus gigas) from the Banyuasin estuarine, South Sumatra, Indonesia. The body weight (BW), prosoma width (PW), carapace length (CL), telson length (TEL), and total length (TL) were measured for describing the morphometric variability of T. gigas. A total of 70 T. gigas (32 females and 38 males) were found using trammel net fishing and bottom gillnet during the survey. Multivariate and allometric methods analyzed their morphometric characters. Based on Kruskal- Wallis tests, the result showed a significant difference in somebody measurements (TL and CL) between males and females. The principal component analysis (PCA) results showed that all morphometric characters had a strong correlation in both sexes, so the first principal component (PC1) values were 92% and 72%. In comparison, the second principal component (PC2) values were 5% and 20% in females and males, respectively. The results of discriminant function analysis (DFA) suggested that only one (BW) of the five morphometric characters was significant in separating both sexes. Both sexes were also revealed variations in growth patterns based on the allometric analysis results. These results were expected to be used as a basis for managing the horseshoe crab population-based conservation.

Multivariate discriminant function analyses were performed on 9 morphometric and 11 meristic characters of capelin (Mallotus villosus) samples at Île aux Coudres in the St. Lawrence estuary; Sept Îles, Natashquan, and Grande Rivière in the Gulf of St. Lawrence; Southeast Shoal on the Grand Banks; and Herring Neck, Notre Dame Bay, Newfoundland. Analyses of meristic characters provided no evidence of discrete stocks. Analyses of morphometric characters provided strong statistical separation between areas. A posteriori classification of groups yielded 93.1% correct classification for males and 73.3% for females. Only snout length, eye diameter, head length, and body depth contributed significantly to the separation obtained. These findings suggest that meristic characters offer little potential for stock identification in Canadian Atlantic waters. Morphometric characters may prove useful, but further study, corroborated with life history and migration data, is required to confirm this. Key words: capelin, Mallotus villosus, meristics, morphometrics, stock separation, Gulf of St. Lawrence, Newfoundland, Canadian Atlantic, multivariate analysis

In this paper, a revision of Chinese Homalopterine fishes is given, comprising 7 genera and 15 species (or subspecies), with the description of a new species, Balito-ropsis yunnanensis, sp. nov. and a new record of Sinogastromyzon tonkincnsis Pellegrin et Chevey in the Chinese fish fauna. The new species is briefly described as follows.Balitoropsis yunnanensis, sp. nov.D. 3.8; A. 2.5; P. 7, 12; V. 2, 8; L. 1. 58, L. trans. 6/6-v..Depth of body contained in standard length 5.9, width of body 5.5, length of head 5.3, length of caudal peducle 5.5, its depth 15.6. Depth of head contained in its length 2.0, width of head 1.1, length of snout 1.9, width interorbital space 2.3, diameter of eye 8.4. Width of mouth contained in width of head 3.5. Depth of caudal peduncle contained in its length 2.8.The present species is similar to Balitoropsis bartschi Smith. But it differs from the latter in having a smaller body depth, much smaller eyes and the larger number of undivided rays in the pectoral fins. The new species can also be distingushed by the larger number of scales in the lateral line and the vent situated nearer to the anal fin than to the ventral base.Type --One specimen, No. 60-Ⅶ-012, kept in the Museum of Institute ofHydrobiology, 58 mm. in standard length, collected in Lanchan River, Yongping Xian, Yunnan Provinee, P. R. China. &amp;nbsp;

The study investigated the morphometric and meristic characterization of Common carp (Cyprinus carpio) sourced from Jos Bauchi and Ibadan (Nigeria). In comparing the morphometric and meristic characters one hundred and eighty (180) adult Common carp, Cyprinus carpio were used. Twenty four (24) morphometric and six (6) meristic characters were studied. Measurements of the morphometric features were taken to the nearest centimeter by means of a measuring board, measuring rule, pair of dividers for the length, while the weight was taken by means of a weighing scale (salter scale) to the nearest gram. ANOVA, multivariate technique principal component analysis (PCA) and discriminant function analysis were also applied to the transformed morphometric data to; classify the fish into one or several mutually exclusive groups. The Morphometric study indicated that seven parameters did not differ significantly (p&gt;0.05) between Jos (male and female), and Bauchi (male and Female) strains. The parameters are the body depth, caudal fin length, pectoral fin height, standard weight, pre dorsal distance, eye diameter and body weight. In the meristic count, only the dorsal fin spine did not differ significantly (p &gt;0.05) among the Jos, Bauchi, and Ibadan strains in all sexes. The study revealed that there was a genetic distance between male and female Carp sourced from Ibadan and that of Jos and Bauchi, where as male and female Carp from Jos and Bauchi showed genetic closeness.

We investigate variations of the basic morphometric characters (length of head, length of snout, diameter of orbit, interorbital distance, etc.) of ten of the most common species of grenadiers (Macrouridae) in the waters of the northern part of the Mid-Atlantic ridge: Coelorinchus labiatus, Coryphaenoides armatus, C. brevibarbis, C. carapinus, C. guentheri, C. leptolepis, C. mediterraneus, C. rupestris, Macrourus berglax, and Paracetonurus flagellicauda. It is shown that most morphometric characters of the investigated species vary within the wider limits as compared with the published data. The representatives of genera Coelorinchus, Macrourus, and Paracetonurus well differ by a number of characters from the species of genus Coryphaenoides and from each other. In spite of a significant likeness in many characters of the species of genus Coryphaenoides, there are individual characters that differ well from one species to another.

European eels are found in all European rivers draining to seas. Comparisons of some morphometric characteristics and length-weight relationship parameters of European eel “Anguilla anguilla” collected from inland waters of Turkey were performed in this work. The 108 fish samples used in the current work were taken from the museum of Faculty of Fisheries, Ege University; they were captured from different running water bodies. Morphometric features like total length, weight, head length, head height, maximum body height, eye diameter, inter-orbital distance, snout length, dorsal fin length, anal fin length, pectoral fin length, predorsal distance, and preanal distance of the fish were measured. In addition, head length/maximum body height, head length/snout length, head length/head height, head length/total length, eye diameter/head length, eye diameter/inter-orbital distance, eye diameter/snout length and predorsal distance/preanal distance ratios were calculated. The analysed specimens ranged in total length from 12.70 to 64.10 cm, and in weight between 3.21 and 416.14 g. The length-weight relationship parameters were estimated as a=0.011, b=3.154; while r2 was calculated as 0.956.

The morphological variation in Schizothorax oconnori, Schizothorax waltoni, and their natural hybrids was examined using conventional and image-based analysis approaches. In total, 38 specimens of S. oconnori, 35 of S. waltoni, and 37 natural hybrids were collected from the Shigatse to the Lhasa section of the Yarlung Zangbo River during June and July 2021. A total of 21 morphometric, 4 meristic, and 27 truss variables were employed for the classification of S. oconnori, S. waltoni, and natural hybrids. Principal component analysis (PCA) and factor analysis (FA), as well as discriminant function analysis (DFA) and cluster analysis (CA), were conducted to identify differences based on traditional and truss measurements. Four principal components explained 75.92% of the variation among the morphometric characters, while five principal components accounted for 79.69% of the variation among the truss distances. FA results showed that factor 1 was associated with head shape, and factor 2 was associated with fins based on morphometric characters. Among the truss characters, factor 1 was related to head shape, and factor 2 was related to chest shape. In DFA, morphometric measurements achieved higher accuracy (100%) compared to truss distances (94.55%). The head morphology of hybrids exhibited intermediate traits between S. oconnori and S. waltoni. Both morphometry-based and truss-based clustering indicated that the morphology of natural hybrids leaned toward S. oconnori. In conclusion, the combination of morphometric and truss analysis is beneficial for classifying S. oconnori, S. waltoni, and their natural hybrids. The presence of natural hybrids could be considered an evolutionary response to the differentiation of nutritional and spatial niches in the middle Yarlung Zangbo River.

This study analyses the ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus (Siluriformes, Pimelodidae), from an ecomorphological standpoint. We collected 241 individuals in the Piracicaba River (Brazil) and, in the laboratory, seven morphometric variables were recorded from each specimen: standard length (SL), body depth, head length, snout length, eye diameter, mouth height and mouth width. After standardizing these measurements (as a proportion of SL), linear regressions were run to determine whether their growth was isometric or allometric in relation to SL. The diet analysis shows that the main food item for fish in the smaller size classes is aquatic insects, while the largest individuals feed mainly on other fish. As the great majority of the morphometric variables analyzed showed isometric growth as a function of SL – which means that these fish do not change their shape significantly during their lives – the ontogenetic diet shifts may be seen as a consequence of the absolute size increment of their mouth gape, which allows individuals to maximize their energetic gain by ingesting larger prey with a higher caloric content.