Condition and morphometric changes in tilapia (Oreochromis sp.) after an eradication attempt in Southern Louisiana

Lorenz, O. Tom; Smith, Patrick W.; Coghill, Lyndon M.

doi:10.3897/neobiota.20.5062

Cited by 3 publications

(3 citation statements)

References 25 publications

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“…Fish farms had on average lower K values than the wild populations. Over-all, among the Table 2 Description of the landmark points, adopted and modified from, (Costa et al 2010;Lorenz et al 2014;Ndiwa et al 2016;Peligro and Jumawan 2016) Landmark number Location description (Fig. 3a).…”

Section: Coefficient Condition (K)mentioning

confidence: 99%

Anthropogenic impacts on the contextual morphological diversification and adaptation of Nile tilapia (Oreochromis niloticus, L. 1758) in East Africa

et al. 2018

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Nile tilapia occurs naturally in East Africa where it's an economically important species. Many of the natural populations of Nile tilapia have been affected by anthropogenic activities including translocations, associated with programmes aimed at enhancing capture fisheries and aquaculture productivity. Using geometric morphometric analyses, we tested the hypothesis that such anthropogenic activities have augmented admixture among natural populations of Nile tilapia and influenced the geographical distribution of morphological variation within the species. Our expectation was that Nile tilapia shape divergent might be consistent with reportedly anthropogenic activities in nonnative environments. To test this hypothesis, we analyzed the shapes of 490 individuals from thirteen populations; three farms, six natives and four nonnative natural populations. Our analysis revealed that the most pronounced shape diversification was observed in seven populations; three nonnatives (Victoria, Kyoga and Sindi farm) and four natives (Albert, River Nile, George and Turkana). The features responsible for the observed morphotypes were mainly related to the orientation of the anterior region of the fish and may be due to diversifying selection in response to new environmental pressures (for nonnative populations), admixture or drift. Shape change in the nonnative high-altitude populations was unexpectedly conserved, suggesting recent introductions which may have not resulted in admixture or there was strong selection against change in the traits measured. On the other hand, the recorded morphotypic clusters explained the possible genetic link to their putative ancestral home. Our results were partially consistent with our prediction that the nonnative populations exhibited divergent morphotypes. We recommend further investigations with molecular genetics for followup of these findings.

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Section: Coefficient Condition (K)mentioning

confidence: 99%

Anthropogenic impacts on the contextual morphological diversification and adaptation of Nile tilapia (Oreochromis niloticus, L. 1758) in East Africa

et al. 2018

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“…This is online with the findings in cichlids species reported by Clabaut et al [1] and Olufeagba et al [4]; in the invasive C. mossambicu Firmat et al [2] and Oreochromis sp. in Southern Louisiana (Lorenz et al [3]).…”

Section: Discussionmentioning

confidence: 99%

“…Changes in body depth and head shape were the main variable in the invasive cichlid Oreochromis mossambicu (Firmat et al [2] and Oreochromis sp. in Southern Louisiana Lorenz et al [3]. Olufeagba et al [4] evaluated morphological variations of cichlids from the Kainji Lake in Nigeria.…”

Section: Introductionmentioning

confidence: 99%

Variability of Morphometric of Oreochromis niloticus, Sarotherdon galilaeus and Coptodon zilli from the Nile and its tributaries in Sudan

Hassan¹,

Mahmoud²

2021

CCIJAVS

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This study assessed morphological variations of Oreochromis niloticus, Sarotherodon galilaeus and Coptodon zilli collected from the Nile and its tributaries. Nineteen morphometric measurements were recorded from each specimen. Data was subjected to discriminant function (CDF) analysis, Wilks' lambda test, t-test and Leave-one-out crosses validation to determine rate of divergence among species. The t-test showed wide variability in the significance (p>0.05 to p0.01) species and site wise in morphometric trait/total length and morphometric trait/head length. The body weight/standard length ratio was consistently significant (p<0.05). Function 1 and Function 2 of CDF clearly separated between O. niloticus and S. galilaeus from Sinnar as well as in Al Sabaloga, and between O. niloticus and C. zilli from Khashm El Girba as revealed by the high significance of Wilks lambda (p<0.003, p<0.000 and p<0.000, respectively). Based on 19 morphometric traits Leave-one-out reclassified the cross validated group at 66.7% and 84.6%, O. niloticus and S. galilaeus from Sinnar, respectively. From Al Sabaloga it reclassified O. niloticus at 97.9% and S. galilaeus at 0.0% due to its small sample size. In Khashm El Girba the cross validated group reclassified O. niloticus at 100% and C. zilli at 94.4%, respectively. Comparison between the values and variables clearly reduced the overlap when 3 traits were used instead of 19 traits. Cluster analysis placed S. galilaeus from Al Sabaloga in a separate branch of the dendrogram due to its small sample size.

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Condition and morphometric changes in tilapia (Oreochromis sp.) after an eradication attempt in Southern Louisiana

Cited by 3 publications

References 25 publications

Anthropogenic impacts on the contextual morphological diversification and adaptation of Nile tilapia (Oreochromis niloticus, L. 1758) in East Africa

Anthropogenic impacts on the contextual morphological diversification and adaptation of Nile tilapia (Oreochromis niloticus, L. 1758) in East Africa

Variability of Morphometric of Oreochromis niloticus, Sarotherdon galilaeus and Coptodon zilli from the Nile and its tributaries in Sudan

A novel catfish cultured in South China is proved to be Silurus asotus based on morphological and molecular genomic identification

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