meristic characters
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2022 ◽  
Vol 5 (1) ◽  
pp. 53-62
Author(s):  
Uğur Karadurmuş ◽  
Rafet Çağrı Öztürk ◽  
Mehmet Aydın

Two specimens of the butterfly blenny, Blennius ocellaris, were caught off the coast of Ordu (Black Sea, Turkey) in April 2021 by trammel net. The aim of this paper is to further document occurrence and distribution of the butterfly blenny for the Black Sea and for Turkish marine ichthyofauna and to provide first morphometric, reproduction, and genetic data on this species to the Black Sea fauna species. Some morphometric and meristic characters were measured and presented as the percentage of total length (TL%). All morphometric measurements except eye diameter, pre-anal length, and maximum body depth were higher in the male individual. It was observed that the head makes up almost 1/4 of the body. It was determined that the ripe eggs were in their final stage of development (Stage IV). Gonad’s weight of a female individual was 2.85 g and the number of eggs was determined as 2993. The mean egg diameter was measured as 1070.7 ±15.63 μm (from 1050.2 to 1123.1 μm). The mitochondrial DNA gene regions of 16S rRNA and COI of the specimens were sequenced and analyzed. The generated partial sequences of COI and 16S rRNA were 621 bp and 551 bp, respectively. The maximum likelihood tree generated with the COI gene sequences retrieved from the GenBank database demonstrated geographic region-based distinction and sequences of the Black Sea specimens nested with the reference specimen sequences from the Western Mediterranean Sea and the Sea of Marmara.


2021 ◽  
Vol 14 (4) ◽  
pp. 1737-1745
Author(s):  
Monalisa Malik Mukherjee

Present study is a first-time report of flathead Sillago, Sillaginopsis panijus (Hamilton, 1822), from Rupnarayan River of West Bengal. Seasonal sampling performed from January 2019- February 2020 by collection of water sample and fish sample in the morning time 5.00 A.M. – 8.00 A.M. A total of 116 specimens of Sillaginopsis panijus (Hamilton, 1822) were collected from four different sampling stations of Rupnarayan river (22.23°N 88.03°E to 22.40°N 87.36°E), West Bengal, India. Present work is a morphometric and meristic data analysis has been provided in detail. Total 23 morphometric characters and 13 meristic characters were analyzed. Morphological characteristics of the species were present to confirm the occurrence and distribution of Sillaginopsis panijus (Hamilton, 1822) along the riverine water of Rupnarayan. The physico-chemical parameters of water have been measured such as temperature of water, dissolved oxygen, pH and salinity. The statistical analysis of multivariate test with post-Hoc analysis and correlation were established with the abundance of S. panijus (Hamilton, 1822) in relation to water parameters. The result shows the dissolved oxygen, temperature, pH and salinity played a most important role in the distribution of S. panijus (Hamilton, 1822). The result shows a statistically significant difference in distribution of fish species, F (12, 8) =18.86, p<0.0005; Wilk’s Λ=0.001, partial η2=0.966. Present study certainly provides the baseline information of Sillaginopsis panijus (Hamilton, 1822) from the Rupnarayan river of West Bengal, India. This record of Sillaginopsis panijus (Hamilton, 1822) may assist the fishery scientist, researchers, policy planners and conservationists to develop sustainable fishery management. Therefore, this study was considered as a first step on morphometric characters for its development and documenting the extension of the distribution and ecological changes in its natural habitat which helps to conserve this species abundance in this area and prevent overexploitation.


2021 ◽  
Vol 71 ◽  
pp. 723-746
Author(s):  
L. Lee Grismer ◽  
Chatmongkon Suwannapoom ◽  
Parinya Pawangkhanant ◽  
Roman A. Nazarov ◽  
Platon V. Yushchenko ◽  
...  

The first integrative taxonomic analysis of the Cyrtodactylus brevipalmatus group of Southeast Asia recovered two newly discovered populations from the Tenasserim Mountains in Suan Phueng District, Ratchaburi Province, Thailand as a new species described here as C. rukhadeva sp. nov. Based on 1397 base pairs of the mitochondrial gene NADH dehydrogenase subunit 2 (ND2), C. rukhadeva sp. nov. is the well-supported sister species to a clade containing three undescribed species, C. ngati, and C. cf. interdigitalis with a large uncorrected pairwise sequence divergence from other species in the brevipalmatus group ranging from 15.4–22.1%. Cyrtodactylus elok and C. brevipalmatus are recovered as poorly supported sister species and the well-supported sister lineage to the remainder of the brevipalmatus group. Cyrtodactylus rukhadeva sp. nov. is putatively diagnosable on the basis of a number of meristic characters and easily separated from the remaining species of the brevipalmatus group by a number of discrete morphological characters as well as its statistically significant wide separation in multivariate morphospace. The discovery of C. rukhadeva sp. nov. continues to underscore the unrealized herpetological diversity in the upland forests of the Tenasserim Mountains and that additional field work will undoubtedly result in the discovery of additional new species.


2021 ◽  
Vol 9 (10) ◽  
pp. 1141
Author(s):  
Alexei Orlov ◽  
Maxim Rybakov ◽  
Elena Vedishcheva ◽  
Alexander Volkov ◽  
Svetlana Orlova

The first records of walleye pollock Gadus chalcogrammus Pallas, 1814 in the seas of the Siberian Arctic (the Laptev Sea, the Kara Sea, the southeastern Barents Sea), are documented. Information about the external morphology (morphometric and meristic characters), photos of sagittal otoliths and fish, and data on the sequences of the CO1 mtDNA gene are presented. The results of a comparative analysis indicate that walleye pollock caught in the Siberian Arctic do not differ in principle from North Pacific and North Atlantic individuals. Previous conclusions about the conspecificity of the walleye and Norwegian pollock Theragra finnmarchica are confirmed. New captures of walleye pollock in the Siberian Arctic allow us to formulate a hypothesis about its continuous species’ range from the coasts of Norway in the North Atlantic to the coasts of Korea, Japan, and California in the North Pacific. The few records of walleye pollock in the North Atlantic originate from the North Pacific due to the transport of early pelagic juveniles to the Arctic by currents through the Bering Strait and further active westward migrations of individuals which have switched to the bentho-pelagic mode of life.


2021 ◽  
Vol 13 (2) ◽  
pp. 250-257
Author(s):  
Margareta Rahayuningsih ◽  
Winda Rahmawati ◽  
Amir Hamidy

Traditionally, the genus Philautus Gistel, 1848 contains small Rhacoporid frogs that lack vomerine teeth and a direct development tadpole stage. In Java, this genus consists of 3 species, including Philautus aurifasciatus, Philautus jacobsoni, and Philautus pallidipes. It is known that Philautus aurifasciatus and Philautus jacobsoni are sympatric species from Mount Ungaran and are morphologically difficult to distinguish. Therefore, information is needed through the phenetic characters of each population in the area to identify differences in their morphology. This study aimed to analyze the morphological characteristics of  Bush Frog Philautus spp. on Mount Ungaran in terms of meristic character through a direct field survey and comparison methods. Furthermore, it was conducted by observing 32 specimens of Philautus spp. from Mount Ungaran and compared with the Philautus aurifasciatus from Mount Gede Pangrango with 18 meristic characters. The results showed that Philautus spp. is similar to Philautus aurifasciatus in terms of their meristic characters. The results of the meristic analysis showed that Philautus spp. has a variety of dorsal colors from brown, purple, green, and gray with two types of patterns including patterned groups (resembling letters H, X, and V) and abstract. Furthermore, the throat, stomach, and lower thighs are granular with three snout shapes (protruding, round, and sloping). It has a loreal oblique tympanum and canthus rostralis. The forelimbs are not webbed while the hindlimbs are half webbed, and the inner metatarsal is an elongated oval in shape. Meristic analysis provides a basis for strengthening the taxonomic status of Philautus spp on Mount Ungaran, as well as information the distribution in Mount Ungaran.


Author(s):  
Bisma Shafi ◽  
T. H. Shah ◽  
F. A. Bhat ◽  
B. A. Bhat ◽  
A. Abubakr ◽  
...  

A study was conducted to analyze morphological characteristics of a Schizothoracid species: Schizothorax esocinus collected from three sites of river Jhelum in Kashmir. S. esocinus is locally known as “Churru” and forms an important food element of the local population., Schizothorax esocinus is one of the most important species in the genus Schizothorax and it has continued to contribute immensely to the nutritional needs, economic growth and development of the Kashmir valley. Furthermore, this fish is very sensitive to any environmental changes so it acts as bioindicator of aquatic pollution. A total of 180 samples were taken for the study of the morphometric and meristic characters utilzing ethnic fishing gears. Thirteen conventional morphometric characters examined in the present study, showed high co-efficient of determination (R2) values ranging from 0.55 to 0.91 for district Srinagar from 0.56 to 0.92 for district Anantnag, and 0.56 to 0.98 for district Baramulla signifying that the traits were highly correlated to each other. Out of six meristic characters examined, two characters were not remarkably different (p>0.05). The fin formula of S. esocinus was devised as D, I + 5-10, P, I + 7-11, C, I + 15-23, A, I + 3-7, LL, 55-170. This study is purely aimed at studying the morphology and meristics of S. esocinus and not at estimating the length-weight relationship or condition factor.


2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 887-894
Author(s):  
M. Sarower-E-Mahfuj ◽  
◽  
S.K. Das ◽  
K.N. Azad ◽  
A.K. Paul ◽  
...  

Aim: Landmark-based truss network system was applied to examine the morphometric and meristic differences among four different populaces of Macrognathus aculeatus namely; Dhakuriabeel, Jashore (DBJ); Arial Kha River, Madaripur (AKRM); Nabaganga River, Jhenaidah (NRJ); Kopotakkha River, Jashore (KRJ) in Bangladesh. Methodology: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Results: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Interpretation: The baseline information derived from the present study would be useful for appropriate conservation of M. aculeatus populations as well as for the researchers for further investigation.


ZooKeys ◽  
2021 ◽  
Vol 1040 ◽  
pp. 91-121
Author(s):  
Korkhwan Termprayoon ◽  
Attapol Rujirawan ◽  
L. Lee Grismer ◽  
Perry L. Wood Jr. ◽  
Anchalee Aowphol

The taxonomy and phylogeny of the Cyrtodactylus pulchellus complex along the Thai-Malay Peninsular region has been the focus of many recent studies and has resulted in the recognition of 17 species. However, the majority of these studies were focused on Peninsular and insular Malaysia where there were specimens and genetic vouchers. The taxonomic status and phylogenetic relationships of the Thai species in this complex remain unresolved, due to the lack of genetic material of some species, especially C. phuketensis and C. macrotuberculatus from Thai populations. In this study, we investigated the phylogenetic relationship between C. phuketensis and its closely related species C. macrotuberculatus, using both morphometric and molecular data. Phylogenetic analyses of mitochondrial NADH dehydrogenase subunit 2 (ND2) gene revealed that C. phuketensis is embedded within a C. macrotuberculatus clade with 1.45–4.20% (mean 2.63%) uncorrected pairwise sequence divergences. Morphological comparisons showed nearly identical measurements of C. phuketensis and C. macrotuberculatus and overlapping ranges in meristic characters. Based on these data, C. phuketensis is considered to be a variant of C. macrotuberculatus, thus rendering C. phuketensis a junior synonym of C. macrotuberculatus.


2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Atul K. Singh ◽  
Abubakar Ansari ◽  
Sharad C. Srivastava

Abstract Background African catfish Clarias gariepinus introduced to India has gravitated into the Ganga River as an invasive species. Morphological plasticity and reproductive adaptation are considered and reported as important manifestation contributing to evolution and persistence of an invasive species in the novel environment facilitating its expansion and establishment. African catfish in the Ganga River although documented to exist, it is yet to investigate if it elicits adaptation responses through morphological and reproductive plasticity in the riverine conditions. Therefore, morpho-meristic changes, plasticity in the reproductive stages, gonadosomatic index (GSI) and gonadal hormones were examined in C. gariepinus that invaded into the Ganga River so as to ascertain its invasion success. Results Out of 23 morpho-meristic characters examined, head length (HL), head depth (HD), anal fin length (AFL) and the pectoral fin rays (PECFR) were observed to differ significantly (p<0.05). The correlation coefficient ‘r’ between log length and log weight was found to be 0.9690 in culture and 0.8754 in river-caught specimens respectively. A distinct deviation in the maturity stages, GSI as well as gonadal hormones (testosterone, estradiol 17-β and vitellogenin) was further observed to change significantly in specimens of African catfish captured from the Ganga River as compared to those available in culture. Highest level of testosterone was found in males having gonadal stage V which was 184.82±10.4 pg/ml in culture and 204.82±21.34 pg/ml in river-captured specimens. The mean value of serum estradiol-17β was lowest (67.25±11.4 pg/ml) in gonadal maturity stage I and highest (328.73±24.5 pg/ml) in stage V in the river-captured C. gariepinus. The vitellogenin level in female C. gariepinus was detected in stage III, and it was maximum in stage V where it was 16.68±2.98 pg/ml in river-captured specimens and 12.63±2.12 pg/ml in cultured fish. Conclusion The results of this study on morpho-meristic and gonadal plasticity provide first evidence of invasion success of the African catfish gravitated in the Ganga River which has now adapted to the river environments for breeding and establishing. The variations concerning different reproductive phases and the gonadal hormones in culture and river-caught C. gariepinus have been considered to contribute to the success of the colonisation and establishment. The knowledge generated on the phenotypic and reproductive plasticity of African catfish available in the Ganga River will help management and control programmes.


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