This study examines the utility of morphology and DNA barcoding in species identification of freshwater fishes from north‐central Nigeria. We compared molecular data (mitochondrial cytochrome c oxidase subunit I (COI) sequences) of 136 de novo samples from 53 morphologically identified species alongside others in GenBank and BOLD databases. Using DNA sequence similarity‐based (≥97% cutoff) identification technique, 50 (94.30%) and 24 (45.30%) species were identified to species level using GenBank and BOLD databases, respectively. Furthermore, we identified cases of taxonomic problems in 26 (49.00%) morphologically identified species. There were also four (7.10%) cases of mismatch in DNA barcoding in which our query sequence in GenBank and BOLD showed a sequence match with different species names. Using DNA barcode reference data, we also identified four unknown fish samples collected from fishermen to species level. Our Neighbor‐joining (NJ) tree analysis recovers several intraspecific species clusters with strong bootstrap support (≥95%). Analysis uncovers two well‐supported lineages within Schilbe intermedius. The Bayesian phylogenetic analyses of Nigerian S. intermedius with others from GenBank recover four lineages. Evidence of genetic structuring is consistent with geographic regions of sub‐Saharan Africa. Thus, cryptic lineage diversity may illustrate species’ adaptive responses to local environmental conditions. Finally, our study underscores the importance of incorporating morphology and DNA barcoding in species identification. Although developing a complete DNA barcode reference library for Nigerian ichthyofauna will facilitate species identification and diversity studies, taxonomic revisions of DNA sequences submitted in databases alongside voucher specimens are necessary for a reliable taxonomic and diversity inventory.

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SummaryA gradient of behavioural patterns was observed among the wild and the first four generations of the African giant rat. Escape reactions and agonistic behaviour were completely lost as from the second generation. Wild rats were easily tamed and those born in captivity were very social. However, being a burrowing rodent, preferring a cool environment in nature, they had a low tolerance to heat. Cannibalism was an important management problem which persisted to the fourth generation resulting in the mortality of 40% of the newly born. From the fifth generation onwards, rats became completely tame and docile. Cannibalism was reduced to less than 10% of the newly born at the fifteenth generation. At this stage, for all practical purposes the giant rat can be regarded as a domestic animal.

The silver butter catfish (Schilbe intermedius) is widely distributed across African river systems. To date, information on its mitochondrial genetic diversity, population structure, and historical demography are not well-established. Herein, we combined newly generated mitochondrial cytochrome c oxidase (COI) subunit I gene sequences with previously published COI sequences in the global databases to reconstruct its phylogeography, population genetic structure, and historical demography. Results from the mtDNA phylogeography and species delimitation tests (Cluster algorithm-Species Identifier, Automatic Barcode Gap Discovery and Poison Tree Process model) revealed that S. intermedius comprises at least seven geographically defined matrilines. Although the overall haplotype diversity of S. intermedius was high (h = 0.90), results showed that East (Kenya) and West (Nigeria) African populations had low levels of haplotype diversity (h = ~0.40). In addition, population genetic polymorphism and historical demographics showed that S. intermedius populations in both East and West Africa underwent severe contractions as a result of biogeographic influences. The patterns of genetic diversity and population structure were consistent with adaptive responses to historical biogeographic factors and contemporary environmental variations across African river systems. This is suggestive of the influence of historical biogeographic factors and climatic conditions on population divergence of S. intermedius across African river systems. Given our discovery of previously

SummaryA study was carried out with weanling African giant rats to evaluate the effect of four dietary crude fibre levels (0, 5, 10 and 15% rice bran inclusion) on their growth performance. There was an increase in feed consumption as the dietary fibre levels increased. Daily body weight gains were not significantly different (P>0.05) between treatments. Protein efficiency ratio (PER) was significantly higher (P>0.05) on the control diet containing no rice bran than on that with 5% rice bran.RésuméUne étude a été menée sur des aulacodés sevrés pour évaluer l'effet de régimes contenant quatre taux de fibres crues différents (0, 5, 10 et 15% de son de riz) sur la croissance. II y a une augmentation de la consommation quand le taux de fibres augmente. Les gains de poids corporel quotidiens ne sont pas significativement diffkrents (P<0.05) selon les régimes. Le taux d'efficience protéinique (PER) est significativement plus élevé (P<0.05) dans le régime ne contenant pas de son de riz que dans celui en contenant 5%.