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Identification of muskellunge, northern pike, and their hybrids
... Although several studies have been published examining the taxonomic status (e.g., Crossman and Casselman, 1969;Casselman et al., 1986;Rab and Crossman, 1994) and distribution patterns (e.g., Crossman, 1966;Crossman, 1978;Maes et al., 2003) of various species of Esox, surprisingly few studies have examined species-level interrelationships. Those studies that did (e.g., Nelson, 1972;Sytchevskaya;1976;Grande, 1999) were narrowly focused, often excluding taxa from analysis or examined an inadequate sample size that did not reflect the geographic range and possible morphological variation within each species. ...
... These teeth form a single row of teeth that runs almost half the length of the vomer. The vomerine tooth patch morphology was used by Casselman et al. (1986) . A one-way ANOVA revealed significant differences in total branchiostegal ray number among taxa (F 0.05, 7, 276 ϭ 174.098 , P Ͻ 0.001). ...
... Casselman et al. (1986) and confirmed by this study, the common condition for Esox is for the abdominal centra to be strongly striated with a very deep dorsal aortic groove. In E. masquinongy however, the centra are only slightly striated and the dorsal aortic groove is shallow. ...
The phylogenetic relationships of extant species of Esox were investigated using both morphological and molecular data. The complete mtDNA cytochrome b gene (cytb) and the second intron of the RAG1 gene were sequenced from multiple specimens of each species and analyzed using maximum parsimony and maximum likelihood. The resulting cladograms were compared with each other and to the morphological cladogram for congruence. Data from all three sources strongly support the monophyly of the genus, and the monophyly of the subgenera Esox (i.e., pikes) and Kenoza (i.e., pickerels). Our data support the sister-group relationship between Esox reicherti and Esox lucius (the Amur and Northern Pike, respectively). Incongruent results between the morphological and RAG1 data and the cytb data, with respect to pickerel interrelationships, suggest hybridization and introgression among pickerel species. Additional research is necessary to explore these results further. This study represents the first study to integrate both morphological and molecular data into a phylogenetic analysis of Esox. It aims to provide a better understanding of esocid evolution and lay the foundation for the interpretation of fossil material assigned to Esox. It also provides preliminary genetic evidence of hybridization among the pickerels.
... [43]. (C), Esox lucius (Esocidae), modified from Casselman et al. [44]. (D), Argyrops spinifer (Sparidae), modified from Randall [45]. ...
Dunkleosteus terrelli, an arthrodire placoderm, is one of the most widely recognized fossil vertebrates due to its large size and status as one of the earliest vertebrate apex predators. However, the exact size of this taxon is unclear due to its head and thoracic armor being the only elements of
its body regularly preserved in the fossil record. Lengths of 5–10 m are commonly cited, but these estimates are not based on rigorous statistical analysis. Here, I estimate the body size of D. terrelli using a new metric, orbit-opercular length, and a large dataset of arthrodires and extant fishes (3169 observations, 972 species). Orbit-opercular length strongly correlates with total length in fishes (r2 = 0.947, PEcf = 17.55%), and accurately predicts body size in arthrodires known from complete remains. Applying this method to Dunkleosteus terrelli results in much smaller sizes than previous studies: 3.4 m for typical adults (CMNH 5768) with the largest known individuals (CMNH 5936)
reaching ~4.1 m. Arthrodires have a short, deep, and cylindrical body plan, distinctly different from either actinopterygians or elasmobranchs. Large arthrodires (Dunkleosteus, Titanichthys) were much
smaller than previously thought and vertebrates likely did not reach sizes of 5 m or greater until the Carboniferous.
... It has been observed that numerous unknown and unexplored details of microstructural features of fish scale can be of remarkable value in identification and classification of fish [9] . The texture, shape, orientation as well as attachment of lepidonts11121314 and thickness, arrangement and relative spacing of circulii around the focus [15] are known to be important in fish taxonomy. From the aforementioned studies, it is clear that scanning electron microscopy of microstructures in fish scale has the potential to differentiate the genera, families, and geographic variants of many fish. ...
Scanning electron microscopy has been identified as an important approach in studying scale microstructures in fish with reference to taxonomy. In this article, a detailed micro-structural analysis of the scales of Channa barca, a poorly known snakehead fish was carried out the location of focus, inter-radial distance, average width and inter-circular space of anterior circulii; inter-circular distance and dentition in lateral circulii; the shape, spacing, length of lepidonts in anterior circulii and the number and width of radii were compared with those of a related species, Channa aurantimaculata. The location of the focus was found to be similar to those of the gachua group of the genus Channa but was different from those of the marulius group. There were major similarities—though with a few notable differences—in scale microstructures between C. barca and the aforemen-tioned closely related species C. aurantimaculata, indicating that scale microstructure analysis has the potential to distinguish even closely related fish species. While several of the microstructural features of the scale were found to be similar to those of the gachua group, others were closer in nature to those of the marulius group. Some microstructural characteristics, however, were found to be totally different from those of both gachua and marulius groups. All of these characteristic features of scale microstructure in C. barca are discussed with reference to taxonomic significance.
... It has been observed that numerous unknown and unexplored details of microstructural features of fish scale can be of remarkable value in identification and classification of fish [9] . The texture, shape, orientation as well as attachment of lepidonts [11][12][13][14]and thickness, arrangement and relative spacing of circulii around the focus [15] are known to be important in fish taxonomy. From the aforementioned studies, it is clear that scanning electron microscopy of microstructures in fish scale has the potential to differentiate the genera, families, and geographic variants of many fish. ...
Scanning electron microscopy has been identified as an important approach in studying scale microstructures in fish with reference
to taxonomy. In this article, a detailed microstructural analysis of the scales of Channa barca, a poorly known snakehead fish was carried out the location of focus, inter-radial distance, average width and inter-circular
space of anterior circulii; inter-circular distance and dentition in lateral circulii; the shape, spacing, length of lepidonts
in anterior circulii and the number and width of radii were compared with those of a related species, Channa aurantimaculata. The location of the focus was found to be similar to those of the gachua group of the genus Channa but was different from those of the marulius group. There were major similarities—though with a few notable differences—in scale microstructures between C. barca and the aforementioned closely related species C. aurantimaculata, indicating that scale microstructure analysis has the potential to distinguish even closely related fish species. While several of the microstructural features of the scale were found to be similar to those of the gachua group, others were closer in nature to those of the marulius group. Some microstructural characteristics, however, were found to be totally different from those of both gachua and marulius groups. All of these characteristic features of scale microstructure in C. barca are discussed with reference to taxonomic significance.
... The 49 specimens from the MNHN and BMNH collections were morphologically identified using the diagnoses of Lucentini et al. [6], Bianco and Delmastro [18], and Casselman et al. [39], using the color pattern of the coat, lateral scales count, and submandibular pores. ...
This integrative taxonomy study of French pikes compares morphological characters and
molecular sequence data (mitochondrial COI and nuclear Plagl2 genes). In addition to the
expected E. lucius, DNA sequences and morphology both support a new species in France,
E. aquitanicus sp. nov. from the Charente to the Adour drainages. It is characterized by a
color pattern of sides with narrow 1–1.5-scale-wide oblique vertical bands, conferring it a
marbled coat, a snout only 0.9 times larger than the postorbital length, an anal fin basis
1.1–1.2 times larger than the caudal peduncle length, 101 to 121 lateral scales, 53 to 57
vertebrae, as well as 24 diagnostic sites in the COI gene and 3 in the Plagl2 gene. Partial COI
sequences (131 bp) from modern and historical specimens indicate also the presence of
E. cisalpinus and E. lucius during the 19th century in Lake Geneva. Morphological and
molecular data points to a possible hybridization between E. lucius with both other local
pike species, representing a risk for them. Their endangerment status should be evaluated
rapidly in order to take conservation measures.
... Thickness, arrangement, and relative spacing of circuli around the focus (Casselman et al., 1986) and the texture, shape, orientation, and attachment of lepidonts (Hollander, 1986;Johal & Dhiman, 2007;Negi et al., 2010;Esmaeili & Gholami, 2011) of the scale are known to be important in fish taxonomy. Ibanez et al. (2007) used geometric morphometric methods to determine if scale morphology can be used to discriminate between genera, species, geographic variants, etc. of mullet (Mugilidae). ...
Scanning electron microscopy (SEM) of scales in six species of the fish genus Channa revealed certain features relevant to taxonomic significance. The location of focus, inter-radial distance and width of circuli, inter-circular space, width of radii, shape and size of lepidonts, etc. were found to be different in different species. The importance of SEM of scales in poorly understood taxonomy and phylogeny of the fish genus Channa is discussed with the help of relevant literature. Further, the role of SEM of fish scales for taxonomic applications is discussed in detail.
Aquatic organisms, especially fishes, exhibit exceptional diversity in mouth morphology and this variation has been shown to influence foraging patterns. We compared mouth morphology among muskellunge Esox masquinongy, northern pike Esox lucius and their hybrid, tiger muskellunge E. masquinongy x E. lucius. Head and mouth size among the three taxa were similar for juveniles (<400 mm total length), but diverged with increasing length, being greater for northern pike than muskellunge. Tiger muskellunge had a head and mouth size intermediate to the two, but more similar to northern pike than muskellunge. Morphological differences among taxa were related to data examining prey size selection in laboratory and field experiments. In the laboratory, northern pike selected prey that were smaller than their maximum mouth width (widest point between outside corners of mouth), tiger muskellunge selected larger prey, and muskellunge size-selection was intermediate between the other two taxa. Among the three esocids, muskellunge had the smallest increase in handling time with increasing prey body depth relative to predator mouth width. In a common garden field experiment in three lakes containing mainly deep-bodied prey, results generally followed morphological patterns, with northern pike selecting larger prey compared to muskellunge. Although morphology predicted most of the variation in greatest body depth of prey consumed, the best predictor of prey size was a model that included predator mouth width, taxon, and interaction. Information comparing prey size selection among esocid taxa is useful for understanding how to manage esocid populations based on system-specific prey characteristics and also for understanding how variations in morphological characteristics of apex predators can influence prey vulnerability and ecosystem structure.
In this paper, we document the first Chain Pickerel (Esox niger) collected in Ontario and the first on the northwestern side of the St. Lawrence River in Canada. The fish was caught by a local commercial fisherman in April 2008. Since 2008, five additional specimens have been caught and are also documented here: three in 2009 and two more through spring 2010. All individuals were mature adults in robust condition. The appearance of Chain Pickerel in the Ontario waters of eastern Lake Ontario and the upper St. Lawrence River may signal an expansion in the range of this species from NewYork state waters.
Growth of muskellunge Esox masquinongy from 12 Ontario sources was investigated by examining 582 samples from the Cleithrum Project archive and other specific studies; 88% of the samples were from angler-caught “trophy” fish. We detail sampling problems and develop methods for resolving them. Muskellunge from some sources were unsexed; sex was discriminated (probability of correct classification, 98.3%) from the von Bertalanffy growth parameters ultimate length (L∞) and growth coefficient, K. When one sex was inadequately sampled, the von Bertalanffy growth parameters of one sex were used to estimate those of the other. When samples were small and inadequate (
We compared growth, survival, diet, and angler catch of muskellunge (Esox masquinongy), northern pike (E. lucius), and tiger muskellunge (E. masquinongy x E. lucius) through 5 yr after their introduction into three Ohio reservoirs. Muskellunge grew slower than northern pike and tiger muskellunge through the first year but faster than northern pike in subsequent years. Large stocked esocids (180-205 mm) survived better than small ones (145 mm). Survival patterns established through the first fall were maintained through age 5; northern pike survived best, followed by muskellunge and tiger muskellunge. Angler catch reflected differences in survival as well as catchability among taxa. Northern pike were caught at smaller sizes and younger ages than other taxa. Gizzard shad (Dorosoma
cepedianum) dominated esocid diets for all taxa and age classes, followed by centrarchids and cyprinids. Prey length consumed increased linearly with esocid length; northern pike selected larger gizzard shad than either muskellunge or tiger muskellunge. These differences in population characteristics among esocids should influence management and stocking programs. Whereas northern pike maximize angling opportunities, muskellunge probably will provide trophy fisheries. Although tiger muskellunge can be reared inexpensively, they appear to provide little
recreational fishing in return.
ResearchGate has not been able to resolve any references for this publication.