The study of the morphometric parameters of the three most abundant species in the lower course of the Kouilou River (Chrysichthys auratus, Liza falcipinnis and Pellonula vorax) was carried out. The standard length of...The study of the morphometric parameters of the three most abundant species in the lower course of the Kouilou River (Chrysichthys auratus, Liza falcipinnis and Pellonula vorax) was carried out. The standard length of Chrysichthys auratus varies between 43.57 and 210 mm, for an average of 96.70 ± 28.63 mm;the weight varies between 2.92 and 140.83 mg, an average of 73.03 ± 21.62 mg. The condition coefficient is equal to 4.42 ± 1.52. Liza falcipinnis has a standard length which varies between 59.9 mm and 158.08 mm for an average of 88.15 ± 29.74 mm;its weight varies between 4.77 and 76.21 mg, an average of 18.61 ± 11.82 mg. The condition coefficient is equal to 2.47 ± 1.57. Pellonula vorax has a standard length which varies between 60.33 mm and 117.72 mm;for an average of 80.48 ± 17.75 mm;the weight varies between 3.61 and 25.17 mg, an average of 9.03 ± 3.61 mg. The condition coefficient is equal to 2.17 ± 0.57. These three species have a minor allometric growth.展开更多
Fish of the Chrysichthys genus are subject to intense exploitation, which is threatening the available stock. The implementation of a sustainable resource management plan requires a good knowledge of the biodiversity ...Fish of the Chrysichthys genus are subject to intense exploitation, which is threatening the available stock. The implementation of a sustainable resource management plan requires a good knowledge of the biodiversity of this genus. The aim of this study was to determine the morphological and genetic characteristics of the fish of the subgenus Chrysichthys chrysichthys in order to identify descriptors for differentiating the species of this subgenus present in C?te d’Ivoire. The biometric analysis involved forty-one morphological measurements taken from each of the 255 specimens sampled in five hydro systems. The genetic analysis of the D-loop mitochondrial DNA sequence was carried out in 34 specimens. The amplicons obtained by PCR were subjected to sequencing. Individual analysis of morphometric characters divided the subgenus into two different species: C. maurus and C. auratus. The high classification rate (>90%) of the Discriminant Factor Analysis confirmed the existence of these two species. Wilk’s Lambda test revealed thirteen discriminating descriptors. Phylogenetic analysis confirmed the existence of both species. Within the C. maurus species, fish from the river Bia are genetically different from those from other rivers. On the other hand, this population is fairly close to that of the C. auratus species, which is also divided into two different clades. Finally, molecular analysis corrected the taxonomic status of the fish.展开更多
文摘The study of the morphometric parameters of the three most abundant species in the lower course of the Kouilou River (Chrysichthys auratus, Liza falcipinnis and Pellonula vorax) was carried out. The standard length of Chrysichthys auratus varies between 43.57 and 210 mm, for an average of 96.70 ± 28.63 mm;the weight varies between 2.92 and 140.83 mg, an average of 73.03 ± 21.62 mg. The condition coefficient is equal to 4.42 ± 1.52. Liza falcipinnis has a standard length which varies between 59.9 mm and 158.08 mm for an average of 88.15 ± 29.74 mm;its weight varies between 4.77 and 76.21 mg, an average of 18.61 ± 11.82 mg. The condition coefficient is equal to 2.47 ± 1.57. Pellonula vorax has a standard length which varies between 60.33 mm and 117.72 mm;for an average of 80.48 ± 17.75 mm;the weight varies between 3.61 and 25.17 mg, an average of 9.03 ± 3.61 mg. The condition coefficient is equal to 2.17 ± 0.57. These three species have a minor allometric growth.
文摘Fish of the Chrysichthys genus are subject to intense exploitation, which is threatening the available stock. The implementation of a sustainable resource management plan requires a good knowledge of the biodiversity of this genus. The aim of this study was to determine the morphological and genetic characteristics of the fish of the subgenus Chrysichthys chrysichthys in order to identify descriptors for differentiating the species of this subgenus present in C?te d’Ivoire. The biometric analysis involved forty-one morphological measurements taken from each of the 255 specimens sampled in five hydro systems. The genetic analysis of the D-loop mitochondrial DNA sequence was carried out in 34 specimens. The amplicons obtained by PCR were subjected to sequencing. Individual analysis of morphometric characters divided the subgenus into two different species: C. maurus and C. auratus. The high classification rate (>90%) of the Discriminant Factor Analysis confirmed the existence of these two species. Wilk’s Lambda test revealed thirteen discriminating descriptors. Phylogenetic analysis confirmed the existence of both species. Within the C. maurus species, fish from the river Bia are genetically different from those from other rivers. On the other hand, this population is fairly close to that of the C. auratus species, which is also divided into two different clades. Finally, molecular analysis corrected the taxonomic status of the fish.
