Interspecific and intraspecific differences in pectoral-fins spine morphology in Nile River and Lake Nasser catfishes, Siluriformes

The structure of the pectoral fins spine of 4 catfish species Heterobranchus longifilis, Clarias gariepinus, Chrysichthys auratus, Synodontis schall and Synodontis serratus were described. The fish specimens were collected from Asyut City and Lake Nasser about 319 and 900 Km south of the capital Cairo, Egypt respectively on 10 November 2017 are described. The species examined showed variation in the shape of the spine-shaft tip varies from finely to broadly and rounded pointed; the curvature of the spine-shaft is either straight or curved partially or complete; the anterior serrae varies between is either broad or irregular; the anterior ridge groove is well developed, deep, and curved, with some pores in some species; the anterior dentations varies between short and sometimes are merged together or curved and their number decreased towards the tip; the posterior dentations can vary between absent or long and numerous and sometimes increased in their number towards the tip of the spine; the dorsal, anterior and ventral processes are well developed structures, with rounded, flange-like, and the shape of the basal fossa varies in having narrow, elongated, boat-shape, with high walls at sides; and very wide fossa and lunate in shape. It is usually deep with high walls.

Caractérisation de la pisciculture dans la région du Poro (Nord de la Côte d’Ivoire)

Cette étude a été menée afin de faire un diagnostic de l’activité piscicole dans la région du Poro. Elle émane des résultats obtenus à l’issu de 2 mois d’enquêtes (mars et avril, 2014) auprès des pisciculteurs. Il ressort que la pisciculture est semi-intensive et pratiquée par des nationaux. La population de pisciculteurs est dominée par des acteurs dont l’âge est supérieur à 45 ans (75%). Les étangs utilisés sont en dérivation. Tous les acteurs fabriquent leur aliment poisson et éprouvent des difficultés à nourrir correctement les sujets. Ils ne bénéficient d’aucun encadrement technique de la part des structures en charge des productions halieutiques. Les espèces majoritairement élevées sont Oreochromis niloticus et Heterobranchus longifilis. La production totale annuelle est estimée à 8 600 ± 1697,1 kg avec un chiffre d’affaires par pisciculteur évalué à 2 876 700 FCFA. Cette activité constitue l’un des moyens de subsistance pour une frange de la population. Sa redynamisation est recommandée afin d'améliorer son impact positif. English title: Characterization of fish farming in the Poro region (North of Côte d'Ivoire) This study was carried out in order to make a diagnosis of the fish farming activity in the Poro region. It emanates from the results obtained after 2 months of surveys (March and April, 2014) among fish farmers. It appears that fish farming is semi-intensive and practised by nationals. The fish farming population is dominated by actors over 45 years old (75%). The ponds used are bypass. All the actors make their fish food and find it difficult to feed the subjects correctly. They do not benefit from any technical supervision from the structures in charge of fish production. The predominantly cultivated species are Oreochromis niloticus and Heterobranchus longifilis. The total annual production is estimated at 8,600 ± 1,697.1 kg with a turnover per fish farmer estimated at 2,876,700 FCFA. This activity constitutes one of the means of subsistence for a segment of the population. Its revitalization is recommended in order to improve its positive impact.

Breeding performance and embryogenic development of three strains of Heterobranchus longifilis in Nigeria

Summary The study sought to investigate the chronology of events and timing of embryogenesis, as well as breeding performances of three strains of Heterobranchus longifilis from Nigeria. Fish samples were collected from Benue River in Makurdi, Niger River in Onitsha, and Rima River in Sokoto for this study. Induced spawning of the strains was carried out so that egg development could be tracked from fertilization to hatching using a simple microscope. The microphotographs obtained showed that the embryogenesis of the strains followed a similar pattern to those of other members of the family Clariidae, however with changes occurring in the specific timing of the sequences of events (i.e. interstrain and interspecies differences). When the different strains were compared, the study noted similarities (P > 0.05) in the overall breeding performance (except for fertilization rate), survival at different stages of development, timing of embryogenesis, and larvae characteristics. The outcomes of this study, therefore, provide baseline information on what genetic improvement of the species through strain crossing can be attempted in future studies.

Sexual dimorphism, metabolic, and oxidative stress markers of African catfish (Clarias garepinus and Heterobranchus longifilis) broodstock in Southwest Nigeria

Background Sexual dimorphism in metabolic and oxidative stress markers of Clarias gariepinus and Heterobranchus longifilis found in southwest Nigeria was investigated. C. garepinus and H. longifilis broodstock weighing 2.54 ± 0.12 and 2.11 ± 0.15 kg consisting of 20 males and females each per species were sourced from southwest Nigeria. Fishes conditioned conditioning for breeding, blood samples were collected, and serum obtained to assess metabolic and oxidative stress indices using standard procedures. Results The results obtained show that serum albumin, triglyceride, low-density lipoprotein, alanine aminotransferase, and total antioxidant activity of Clarias garepinus were significantly (p < 0.05) higher than Heterobranchus longifilis. Superoxide dismutase of males was significantly (p < 0.05) superior to females in both species. The total antioxidant activity of males was significantly (p < 0.05) superior to females in Heterobranchus longifilis. Serum catalase, glutathione peroxidase and lipid peroxidation were not affected by sex and species differences. Superoxide dismutase activity and some non-enzyme antioxidants could account for superior total antioxidant activity in males despite similar lipid peroxidation. Conclusion Catfish broodstocks of Heterobranchus longifilis possess superior total antioxidant activity than Clarias gariepinus owing to its superior non-enzyme antioxidants fraction. In both clariid species, males have better antioxidant defence than females.

Cestode infections of two clariid and two claroteid catfish species in River Galma, Zaria, Nigeria

Four catfish (Siluriformes) species comprising two clariids, Heterobranchus bidorsalis (65) and Heterobranchus longifilis (15) and two claroteids, Auchenoglanis occidentalis (31) and Chrysichthys auratus (19) from River Galma Zaria, Nigeria, were examined for gastrointestinal cestodes between May 2016 and February 2017. Helminths recovered were stained, dehydrated, cleared and mounted in Canada balsam for microscopic examination. A total of seven cestode species were recovered from the clariids and claroteids. The cestodes were distributed among the fish examined as follows: in C. auratus: Wenyonia longicauda (26.32%), W. virilis (10.53%), and W. minuta (5.26%); in H. bidorsalis: W. acuminata (3.08%), W. virilis (18.46%), Monobothrioides woodlandi (6.15%), Proteocephalus sp. (1.54%) and Tetracampos ciliotheca (4.62%); in H. longifilis: M. woodlandi (6.67%), W. longicauda (6.67%) and W. acuminata (6.67%). Prevalence of cestode infection in C. auratus was higher in the wet than in the dry season; however, prevalence of infection in H. longifilis and H. bidorsalis was higher in the dry than in the wet season. The prevalence was higher in male than in female H. longifilis while higher in female than in male C. auratus and H. bidorsalis. Prevalence decreased with increase in standard length of C. auratus, H. longifilis and H. bidorsalis. A seemingly posteriorly deformed W. minuta was recovered from C. auratus. None of the 31 A. occidentalis examined in this study was infected by cestodes. All the fish used in this study were collected mostly on the basis of availability. It is therefore recommended that larger sample of assorted sizes be obtained, especially of H. longifilis (15) and C. auratus (19), of which very few specimens were examined during the period of this study to obtain a clearer picture of infection by the cestodes from RiverGalma, Zaria, Nigeria. Keywords: Cestodes; catfish; clariid claroteid; siluriformes; infection; prevalence; intensity.

Length-weight relationship and condition factor of Clariid fish species in Kano Rivers, Kano State, Nigeria

Fish found in natural tropical and sub-tropical water system experience frequent growth fluctuations. The study was conducted to determine the length-weight relationship and condition factor of Clariid species (Clarias gariepinus, Heterobranchus longifilis and Synodontis clarias) in Kano state of Nigeria. About 177 fish samples were collected from six rivers (Thomas, Ghari, Tiga, Duddurun-Gaya, Karaye and Bagwai) across the length and breadth of Kano state. Body weight (BW=248.48g), total length (TL=32.74cm) and standard length (SL=26.16cm) were determined. The length-weight relationship and condition factors were also determined. The condition factors showed varying degree of well-being of fish sampled from their habitat, and ranged from K = 0.37 to 0.89. The equation for the lengthweight relationship for the three strains is: C. gariepinus = -329.86+17.56TL, H. longifilis = -241.49+14.28TL and C. clarias = -428.51+22.72TL. Body weight and length had positive and significant relationship (r = 0.73 TL; r = 0.75 SL).

Comparative genetic and morphometric characterization of sympatric populations of Heterobranchus bidorsalis and Heterobranchus longifilis

African catfish species of Heterobranchus longifilis and H. bidorsalis are gaining breeding potentials and receiving great attention among catfish stakeholders. However, very few comparative research works have been done on the natural populations and cultured stocks of these economically important species. In this study, the genetic evaluation of the fish species populations obtained from Lake Kainji, New Bussa, Niger State, Nigeria, was conducted through Sodium Dodecyl Sulphate - Polyacylamide Gel Electrophoresis oftheir serum proteins, and morphometric evaluation. Morphometric data showed that adipose fin attributes [length; depth (cm), % standard length (SL)] of 23.4±1.1; 4.2±0.5 in the H. bidorsalis confirmed its hyper-development compared to H. longifilis of 25.7±3.2; 4.4±0.6 respectively. The pre-dorsal length gave higher value (%SL) in the H. longifilis (38.6±2.2) than H. bidorsalis (34.6±1.2); while H. bidorsalis further possessed more counts at dorsal and anal fin rays than H. longifilis. The comparative dendrogram of the PAST analysis showed a genetic distance of 4.2% that indicated the specificity of these species and, though significantly different, they had very close relationship. Therefore, proper identification of these species is highly necessary to maintain genetic purity in breeding programmes and biodiversity.