Revision of the diagnostic characters of two morphologically similar snook species, Centropomus viridis and C. nigrescens (Carangiformes: Centropomidae)

Zootaxa ◽  
2021 ◽  
Vol 4915 (3) ◽  
pp. 326-338
Author(s):  
JUAN MANUEL MARTÍNEZ-BROWN ◽  
JAIME NAVARRO-FLORES ◽  
FRANCISCO JAVIER GARCÍA-RODRÍGUEZ ◽  
LEONARDO IBARRA-CASTRO ◽  
CARMEN ELVIRA VARGAS-PERALTA ◽  
...  

Historically, the taxonomic identification of the two snook species, Centropomus viridis and C. nigrescens, has been challenging due to their morphological similarity and the inconsistency of the characters used for diagnosis. Therefore, this study aimed to evaluate the usefulness of the morphologic, meristic, and morphometric characters currently being used to identify C. viridis and C. nigrescens, based on molecular data. The results showed that the gas-bladder shape (i.e., C. viridis with diverticula and C. nigrescens without diverticula) was the only morphological character univocally related to genetic identification. Likewise, geometric morphometrics separated two groups; each corresponds to only one of two genetically (and gas bladder shape) identified species. Of all the meristic characters examined, only the second dorsal fin ray count (nine for C. viridis and ten for C. nigrescens) was related to the gas bladder shape and genetic identity; therefore, it is the only external character with a diagnostic utility to separate each species. 

1982 ◽  
Vol 39 (12) ◽  
pp. 1664-1685 ◽  
Author(s):  
I-H. Ni

The distribution of Northwest Atlantic beaked redfishes, Sebastes mentella and S. fasciatus, has been confused for the past several decades. Sebastes fasciatus has been reported as having lower meristic counts than S. mentella. Meristic elements of 33 301 vertebrae, 22 622 anal fin ray, and 16 290 dorsal fin ray counts were utilized to examine the yearly, depth, and geographic variation of meristics in beaked redfishes. Data collected from specimens caught off West Greenland, Baffin Island, Labrador, Newfoundland, Quebec, and Nova Scotia were analyzed by 100-m-depth intervals. Temporal and depth variation were examined by the χ2-test of independence on meristic frequencies. Geographic variation was evaluated using the modes and mean values in the meristic frequency histograms. Cluster analysis of meristic frequencies displayed the dendrographic affinities and the distance matrix among division–depth blocks.Temporal variation indicated a mixture of vertebral frequency patterns which varied with depth and area. Depth variation and geographic clines were found for each of these meristic characters; the shallow and southern waters were dominated by counts of 29, 14–13, and 7 for vertebrae, dorsal fin rays, and anal fin rays, respectively, whereas deep and northern waters were dominated by 30, 15–14, and 8–9. These results suggested that S. fasciatus occurs on the Nova Scotian Shelf and Grand Bank whereas S. mentella is largely found in Baffin Bay, Labrador waters, and the Gulf of St. Lawrence. The common names of S. mentella and S. fasciatus are discussed. Additionally, five hypothetical stocks of beaked redfishes based on meristic patterns are proposed for management purposes.Key words: Sebastes mentela, S. fasciatus, redfish, meristic variation, distribution, cluster analysis


2018 ◽  
Vol 10 (1) ◽  
pp. 8-13
Author(s):  
Muthusamy THANGARAJ ◽  
Ramachandran KUMARAN ◽  
Shanmugam CHANDRASEKAR

Morphometric and meristic analysis of ladyfish, Elops machnata, were used to discriminate stocks along the Southeast and Southwest coast estuaries of India. Morphometric and meristic analyses showed a similar pattern of differentiation between E. machnata stocks and revealed a clear discreteness of two groups, an East coast (Marakanam, Parangipettai and Muthupettai) population and a West coast (Cochin) population. Higher total length (TL) (28.00 ± 7.043 cm), fork length (FL) (89.27 ± 2.201% TL) and standard length (SL) (81.77 ± 2.582% TL) were recorded in Cochin population and they were significantly different from the other three populations. Meristic counts were relatively homogenous in all the studied populations. No significant variation was found in counts of dorsal fin ray (DFR), anal fin ray (AFR), pectoral fin ray (PFR) and pelvic fin ray (PLFR). The first and second components (PCA analysis) accounted for about 92.2% of variation in all the morphometric characters. Among them, pre pectoral length (PPL) and pre dorsal length (PDL) showed high loading values in PC1 in all four populations. The overall random assignment of individuals to their original group was higher in morphometric than in meristic analysis. Such a presumption could be authenticated henceforth with molecular markers. Hence, further studies, using molecular markers are still required to precisely evaluate the genetic structure of E. machnata along the Indian coast.


Zootaxa ◽  
2021 ◽  
Vol 4974 (1) ◽  
pp. 135-150
Author(s):  
BARAN YOĞURTÇUOĞLU ◽  
CÜNEYT KAYA ◽  
JÖRG FREYHOF

Oxynoemacheilus nasreddini, new species, from Lake Akşehir, Eber, Eğirdir, and Ilgın basins in Central Anatolia is distinguished from other species of Oxynoemacheilus in Central Anatolia by having irregularly shaped blotches on flank; 2–4 dark-brown bands on caudal fin; a slender body, and an emarginate caudal fin in which the shortest middle caudal-fin ray is 76–91% of the longest ray of the upper caudal-fin lobe. Molecular data suggest that the new species is closely related to O. mediterraneus from the Aksu and Köprüçay drainages. Although the two species are separated by only a minimum K2P distance of 1.2% in the mtDNA COI barcode region, they are well distinguished morphologically. The situation is complicated by loaches from Lake Eğirdir basin that are identified as O. nasreddini by their morphological character states but are only distinguished from O. mediterraneus by a minimum K2P distance of 0.2% in the mtDNA COI barcode region. 


Zootaxa ◽  
2017 ◽  
Vol 4344 (3) ◽  
pp. 541 ◽  
Author(s):  
FRANZ UIBLEIN ◽  
TUAN ANH HOANG ◽  
DANIEL GLEDHILL

For Jansen’s goatfish, Parupeneus jansenii (Mullidae), taxonomic knowledge has been rather poor and occurrence information restricted to a few localities only, with verified records from northern Sulawesi and Sunda Street (Indonesia), and Luzon (Philippines). This species is here included in the so-called “heptacanthus” group together with the Indo-Pacific cinnabar goatfish, P. heptacanthus, and five Indian Ocean congenerics, based on an evenly, symmetrically rounded posterior maxilla margin and similarities in meristic characters and preserved colour. In total 29 P. jansenii and 53 P. heptacanthus consisting of types, recently collected material from south-central Vietnam, southern Indonesia, and NE Australia, and geographically related reference material were studied along with single types of the other five heptacanthus-group species and P. angulatus, a morphologically similar Western Indian Ocean species. In total 62 quantitative meristic and morphometric characters including standard length (SL) were analysed after splitting the data into two size classes (small-sized fish, < 110 mm SL, vs. large-sized fish  > 110 mm SL) to account for size-related differences due to allometry. Diagnoses for P. jansenii and P. heptacanthus and a redescription for P. jansenii were prepared. Fresh-fish colour descriptions for both large- and small-sized voucher specimens of P. jansenii are provided and the effects of freshness status on colour patterns is documented. New records for P. jansenii for Vietnam, southern Indonesia and NE Australia (= first verified record for Australia) are reported and depth information (24–100 m depth range) is given for the first time. P. jansenii differs from the co-occurring P. heptacanthus - independently of size - in shallower body and caudal peduncle, smaller maximum head depth, shorter barbels, caudal and pelvic fins, shallower first dorsal fin, shallower first ray of second dorsal fin, and lack of small dark red or reddish-brown spot on or just below the eighth lateral-line scale. The populations of P. jansenii from Vietnam and Australia differ from each other in a single character, the height of the eighth dorsal-fin ray, but both overlap with the intermediate population from Indonesia. This comprehensive alpha-taxonomic approach provides a useful tool for uncovering the diversity of Parupeneus goatfishes. 


2020 ◽  
Vol 28 (3) ◽  
pp. 230-237
Author(s):  
Y. S. Nikulina ◽  
K. V. Polyaeva

In the present study, we present an analysis of the morphological and ecological characteristics of the “turukhanskaja” form of the Siberian least cisco of the Yenisei River, including the characters of the size-age, sexual composition of the population, fecundity and growth. The variability of 34 morphological characters was studied. Significant differences were noted between males and females of the least cisco of the Yenisei River for 11 morphometric characters (head length, maximum body depth, caudal peduncle length, antepectoral distance, dorsal fin base length and dorsal fin depth, anal fin base length, pectoral fin length, head width, head (at nape), interorbital width). Significant differences in meristic characters were revealed in comparison of the least cisco from the Yenisei River with populations of Siberian least cisco from other water bodies. It was shown that the Yenisei least cisco is close to the European vendace Coregonus albula Linnaeus, 1758 not only according to cluster hierarchical analysis for some meristic and morphometric features but also in terms of growth and fecundity. In general, the Yenisei least cisco, as well as other populations of least cisco of the Taimyr, is characterized by heterogeneity in the structure of populations. The parasite fauna of Yenisei’s Siberian cisco, captured in the area of Dudinka town, consists of 17 species of parasites from seven systematic groups. It is dominated by Diphyllobothrium ditremum (Creplin, 1825) and Discocotyle sagittata (Leuckart, 1842). The feature of the parasite fauna of least cisco from Yenisei River in comparison with the Ob River (neighbouring water basin) is a low infection with trematodes and a high species diversity of Acanthocephala. The reason for the low infection with trematodes may be differences in the hydrological conditions of the water bodies, which in the Yenisei are unfavourable for the development of intermediate hosts of trematodes. Siberian cisco from the Yenisei River is a carrier of Diphyllobothrium dendriticum (Nitzsh, 1824), a species that can cause human disease.


2013 ◽  
Vol 11 (2) ◽  
pp. 307-318 ◽  
Author(s):  
Adrian F. Gonzalez-Acosta ◽  
Rocio Rodiles-Hernandez

Eugerres castroaguirrei, new species is described from the río Grijalva-Usumacinta basin of southeastern Mexico and northern Guatemala. Eugerres castroaguirrei and E. mexicanus are distinguishable from their marine estuarine congeners by the dorsal-fin origin posterior to the insertion of the pectoral and pelvic fins, a shorter and broad based supraoccipital crest, and a distinct geographic distribution restricted to freshwater habitats. Eugerres castroaguirrei differs from E. mexicanus by diagnostic characters of the body skeleton: anterior process of supraoccipital convex, infraorbital 1 with foramen, premaxillary ascending process developed with margins curved, pharyngeal plate granular and not serially arranged, and dorsal and anal fin-rays reduced. Likewise, E. castroaguirrei is characterized by an oblong and laterally thicker body (37.6-58.5% HL); greater body depth (33.8-42.1% SL), and eye diameter (23.3-31.6% HL); in addition to 16 significant morphometric characters: length of the second dorsal-fin spine 23.2-34.2% SL; depressed second dorsal-fin spine (extending to base of third to fourth dorsal-fin rays); length of second anal-fin spine 11.1-20.6% SL, depressed second anal-fin spine extending to the base of third to fourth anal-fin rays not reaching the distal point of last anal-fin ray; pelvic-fin spine length 49.7-65.0% in the first pelvic-fin ray length


2018 ◽  
Vol 124 (4) ◽  
pp. 718-731 ◽  
Author(s):  
Juan Mauro Chiarello-Sosa ◽  
Miguel Ángel Battini ◽  
Juan Pablo Barriga

Abstract Body shape and meristic characters are highly variable phenotypic aspects in fish, and in most cases are related to phylogeography, environmental factors and life history patterns. Our main goals here were to evaluate morphological and meristic characters in five populations of the catfish Hatcheria macraei living at different latitudes across Patagonia, and to assess the importance of environmental and phylogenetic variables in determining body shape. The present study reveals great morphological variation among populations distributed along the latitudinal gradient. We found that the highest levels of variation in external morphological features were in peduncle height, dorsal fin length and anus position. This variation in body shape, quantified by geometric morphometrics, was mostly explained by the phylogenetic relationship between populations, stream gradient and spawning temperature. In contrast, the meristic characters, such as vertebral and fin ray numbers, except for dorsal fin ray number, were negatively related to latitude and positively to spawning temperature.


1991 ◽  
Vol 69 (2) ◽  
pp. 274-278 ◽  
Author(s):  
Terry D. Beacham

Heterozygosity of 26 pink salmon (Oncorhynchus gorbuscha) families was compared with family survival rates up to 410 d after fry emergence and also with asymmetry of pectoral and pelvic fin ray numbers. There was no significant association between heterozygosity calculated at six electrophoretic loci and either survival rate or asymmetry in fin ray number at any time during the 410-d rearing period. More heterozygous families did not have higher survival rates than less heterozygous families, and they did not have less asymmetry in the fin ray characters. Heritabilities of 11 morphometric characters were, on average, lower than the heritabilities of the 2 meristic characters examined. There is no evidence yet to indicate that increased heterozygosity results in increased canalization of morphology in pink salmon.


2020 ◽  
Vol 20 (2) ◽  
pp. 189
Author(s):  
Muhammad Nur ◽  
M.Fadjar Rahardjo ◽  
Charles P.H. Simanjuntak ◽  
Djumanto Djumanto ◽  
Krismono Krismono

Pirik (Lagusia micracanthus Bleeker, 1860) is one of endemic fishes in Sulawesi. Morphometric and meristic information of Pirik population in various habitats are unknown. The present study aimed to determine the morphometric and meristic variation of Pirik in Maros and Wallanae Cenrana watersheds. Sampling collection was carried out monthly from May 2018 to April 2019 in the Maros watershed, namely Pattunuang River (M1), Bantimurung River (M2), Pucak River (M3); and in Wallanae Cenrana watershed particularly in Camba River (W1), Sanrego River (W2), and Ompo River (W3). Morphometric measurements consisted of 31 characters and meristic measurements consisted of 10 characters. Morphometric data was standardized by dividing all morphometric characters by standard length (SL). Analysis of variance (ANOVA) and discriminant analysis (Discriminant Function Analysis) were applied for data analysis. The results showed that the Pirik taken from rivers in the Maros and Wallanae Cenrana watershed are two different population groups. There are 12 distinguishing morphometric features for Pirik of the Maros and Wallanae Cenrana watershed, i.e. TL (total length), SL (standard length), BDdSA (body depth-dorsal fin origin), HL (head length), Jlup (upper-jaw length), PAfL (pre-anal fin length), ABL (Anal fin base length), PelRL (pelvic ray length), AFRL (anal fin ray length), CPL (caudal peduncle length), CLLup (upper caudal lobe length) and CLLmid (mid-caudal length). There is no significant difference of meristic characters of Pirik obtained from the Maros and Wallanae Cenraa watersheds.


Author(s):  
Eze Felix ◽  
Eyo Victor Oscar ◽  
Abraham Oghenemarho Victory

This research was carried out to study the morphological characteristics of Coptodon zillii from Lake Komadugu in Yobe State, Nigeria using morphometric measurements, meristic counts and length-weight relationship. A total of 60 specimens of Coptodon zillii were purchased from the fisher folks at landing site in Lake Komadugu, examined and analyzed for morphometric and meristic characterization. The results revealed that all the morphometric characters of C. zillii in Lake Komadugu varied whereas some meristic characters including mean number of rays on pectoral fin (8.00 ± 0.00), pelvic fin ray (5.00 ± 0.00), anal fin spine (3.00 ± 0.00), pelvic fin spine (1.00 ± 0.00) and number of lateral line (2.00 ± 0.00) were constant. A significant linear relationship was established and represented by the equation: W =0.008SL2.097 (r =0.6410 d.f. = 58) for male, W =0.001SL3.013 (r = 0.9600 d.f. = 58) for female. Mean condition factor which was not significantly different (p>0.05) showed that male C. zillii had 1.80 ± 0.27, female (1.92± 0.26) and pooled sex (1.86 ± 0.25). Findings of this study implies that C. zillii from Lake Komadugu are in good health. In conclusion, these findings are very useful in stock assessment, population dynamics, sustainable management and conservative measures of C. zillii in Lake Komadugu.


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