Food and Feeding Habits of Atya gabonensis from Lower River Benue in Northern Nigeria

The study investigated the stomach content of Atya gabonensis from lower River Benue in Nigeria from January 1998 to January 2000.The stomach analysis was carried out using frequency of occurrence and numeric methods. It was observed that the organism fed on algae, diatoms, insect parts and detritus, algae and detritus forming the most important food items. Algae constituted 61.9% of food item by number and 88.5% by occurrence. Detritus occurred in 79.1% of stomachs examined. Amongst the algae, Scenedesmus quaricauda was the most preferred, constituting 20.7% by occurrence and 37.9% by number, followed by spirogyra which constituted 17.8% and 23.9% by occurrence and number, respectively. The least eaten food item was insect parts. A. gabonensis can be said to be an omnivorous detrivore, its preference for food changing with season and size of the prawn with peak in July.West African Journal of Applied Ecology Vol. 13 2008: pp.77-8

The Impact of Environmental Contaminants on Women’s Reproductive Health

Individuals are exposed to many environmental toxins daily in their home, workplace, community and farmland. Several studies have demonstrated that women in their physical, biological, social, cultural and technological interactions with the environment, are exposed to various harmful environmental contaminants which act as endocrine disrupters in their bodies. They tend to affect endocrine homeostasis and impair reproductive functions. When they gain access into the body , they interfere with the production, release, transport, metabolism and other actions performed by the body’s natural hormones leading to hormonal disorders, reduced fertility, preterm delivery and  uterine cancer later in life.  Lifestyle modifications through health  education  programmes could help to minimize the level of exposure and risks to these environmental chemicals. Key words:  Environment, Contaminants, Women, Reproductive healt

Migration in fishes: a review

A review of migratory activity in fishes reveals that migration is important for the completion of life cycle. Recent studies have increasingly demonstrated the wide spread existence of spatio-temporal variations in the abundance and distribution of species of freshwater fishes, previously assumed not to move between habitats. These movements are often for spawning, feeding and refuge, and in many cases are fundamental for the successful completion of life cycles. Chemical and physical changes in water environment affect the migration of fish. Most fish undertake feeding, breeding or wintering migrations. A number of studies have documented the influence of freshwater and ocean conditions, climate variability and human impacts resulting from impoundment and aquaculture on fish migration

Fecundity and Gonad Development of Atya Gabonensis from Lower River Benue in Northern Nigeria

The study investigated the fecundity and egg development of Atya gabonensis from Lower River Benue in Nigeria from May to August 2006. A total of 200 berried females were collected, weighed and the eggs striped and weighed using a top loading electronic balance. The total length of the prawn was also measured using a ruler to the nearest millimeter. The eggs were preserved in Gilson's fluid. The total number of eggs was estimated by the gravimetric method. The egg size was measured using the calibrated eye piece of a binocular microscope. The eggs were classified as immature, developing and ripe with two 'eye' spots called the larva stage. The highest number of eggs observed was 27,700eggs, while the lowest was 950 (mean = 7,227eggs). The egg diameter ranged from 0.02 2mm (0.63 ± 0.10mm). The relationship between fecundity and weight was F = 3.799 + 8.2400W (r = 0.7887), while the one between fecundity and length was F = 5.6067 + 1.9386L (r = 0.7504). There was positive correlation between length, weight and fecundity in A. gabonensis from Lower River Benue. The appearance of eggs in May to August coincides with onset of rain therefore rain is a triggering factor in egg production. A. gabonensis is a serial spawner as the berried females were found to carry eggs in various stages of development

Checklist and Assessment of Efficiency of Some Traditional Gears and Crafts Used on River Benue

The study was carried out in 2006 from January to October. This covered the dry season and the rainy seasons of the year. The work was carried out along the Lower River Benue. The data were collected monthly using questionnaires and taking photographs of the crafts and the gears by visiting the fishing areas of Abinse, Wadata, Agatu and Kastina Ala. More than half of the one hundred and fifty species of fish native to Nigerian waters were caught in commercial quantities using these gears. A few types of selected gears seem to be distributed according to tribal patterns. It is on this basis that one hears fishers saying “why should I use the Jukun, Tiv, or Hausa type of gear”. In most cases, fishermen will always choose the most efficient type of gear despite the tribal affiliations. The efficiency and use of the gears and crafts was also seasonally based. The commonest gears observed during the study were scoop net, doubled chamber cane trap, woven trap, and Malian trap. In addition, most of these gears were found to be more efficient on predatory fishes. It was also observed during the course of this study that the cost of making these gears is relatively low compared to the imported types. The commonest crafts observed during the study were spear, knife, machete, planked canoe, dugout canoe and calabash. The traditional gears and crafts were cheaper than the imported ones therefore easily affordable by the local fisher forks. The spears and machetes were used as accessory instruments while fishing. The gears were observed to be either passive or active gears

Length-weight relationship, diet composition and condition factor of Clarotes laticeps from Lower River Benue

Length weight relationship, diet composition and condition factor of 240 samples comprising of 79 male and 161 female of C. laticeps from Lower River Benue was determined. The mean total length, standard length, body weight, and condition factor of male Clarotes laticeps were 33.30±1.10, 27.70± 1.07, 464.30±465.03, and 1.05±0.05 respectively while the mean total length, standard length, body weight and condition factor of the female counterpart were 35.80±1.13, 29.33±1.05, 528.20±467.85 and 0.97±0.04 respectively. There was no significant difference (p > 0.05) in the mean total length, standard length, body weight and condition factors between the male and female Clarotes laticeps. Female Clarotes laticeps had better ‘b’ value (3.13) than the males (3.01). Of the 240 C. laticeps examined, 35.00% samples had empty stomachs while 65.00% samples had different food items in their stomachs. Out of the 65.00% stomachs containing different food items, 31.40 % had full stomachs, 26.30 had half-full stomachs, 19.20% had quarter stomach while 23.10% had three quarter-full stomachs. Varieties of food items found in the stomachs C. laticeps ranged from plant to animal materials as well as sand and detritus. The most frequently food item consumed by C. laticeps was algae (85.90%) while insect part (20.12 %) had the least. Numerically, algae (37.24 %) had the highest while digested food particles (6.90%) was the least food item consumed.Keywords: Length-weight, Diet composition, Clarotes laticeps, Condition factor and River Benu

Morphological and parasitological variations of African lungfish, Protopterus annectens in dry and rainy seasons

This study was carried out to determine the seasonal morphological and parasitological variations of African Lung fish (Protopterus annectens) from Upper River Benue, Nigeria. Twenty specimens each of the fish samples from the two seasons were collected monthly for a period of ten months and transported fresh (alive) to the Veterinary laboratory Teaching Hospital, University of Agriculture, Makurdi in plastic jars. The fish samples were identified and sorted into male and female. The total and standard lengths measurements were recorded while the weight was measured. Length weight relationship was determined. Examination for parasites on the fish samples was carried out. Parasitic indices (prevalence (%), and mean intensity, percentage parasite load and percentage frequency of occurrence of each parasite species per location in fish were calculated. The mean total length, total body weight and condition factor of Protopterus annectens in dry season were 36.25cm±0.67, 515.60g±25.90 and 0.91±0.023, respectively while in rainy season, the mean total length, total body weight and condition factor of 34.74cm±0.63, 460.60g±24.20 and 0.91±0.019, respectively. There was no significant difference (p > 0.05) between the mean total lengths, total body weight and condition factor of the fish sample in both seasons. Out of the 400 samples of P. annectens used for the study in dry and rainy seasons, 31.75% were infested with 242 different parasites. Of the total parasites, 50.83% parasites were recorded in dry season from 67.00% infested fish samples while 48.40% parasites were recorded from 32.00% infested fish. Of the parasites species, Contracaecum sp was the most prevalent (34.15%) in dry season. This parasite accounted for 18.70% in the intestine and 15.45% in the stomach while Eustrongyloids sp was the most prevalent (27.36%) in rainy season accounting for 22.64% in the intestine and 4.72% in the stomach. The least prevalent parasite load (3.25% in dry season and 2.83% in rainy season) was recorded for Trichodina sp. Among the body organs of the fish samples, intestine recorded the highest percentage parasite load (50.41%) in dry season while stomach had the highest percentage parasite load (49.06%) in rainy season. The least (3.25% in dry season and 2.83% in rainy season) were recorded for skin. Generally, intestine had the highest percentage parasite load (98.52%) with 50.41% in dry season and 48.11% in rainy season. Female P. annectens from both seasons had more percentage parasite loads (61.79% in dry season and 53.77% in rainy season) than the male P. annectens in both seasons (38.21% in dry season and 46.23% in rainy season). There were variations in percentage parasite load among the length and weight groups of the fish samples and conclusively, higher percentage parasite load (50.83%) was recorded in dry season than the rainy season (48.40%).Keywords: Protopterus annectens, parasites, dry and rainy seasons and upper River Benu

Fish hybridization in some catfishes: a review

A review of hybridization of some catfishes shows that catfish hybridization among other aspects of biotechnology has continued to raise interest among researchers of various disciplines such as fish biologists, geneticists, aquaculturists, molecular biologists, nutrion scientists and so on. The studies so far reported were from seasoned researchers from several works of life and disciplines who have direct or indirect interest in fish hybridization (especially catfishes). It could be thus, concluded that though there is a dearth in literary work on catfish hybridization considering their numbers and diversities. However, several interesting works can be found across continents (especially Africa, Asia, and North America) that shows that catfish hybridization holds a very high potential for the future. Better catfish hybrid is equivalent to a better catfish aquaculture as well as it contribution to global food security

Influence of physico-chemical parameters on the distribution of freshwater snails in River Uke, Nassarawa State, Nigeria

The Physio-Chemical parameters of River Uke, Keffi, Nasarawa State, were studied between the months of February to August 2011. Nine water parameters were analyzed and Melanoides tuberculata was also identified using identification keys by Brown and Kristensen (1993). These include temperature, pH, alkalinity, turbidity, conductivity, nitrates, phosphates, total dissolved substances and dissolved oxygen using the methods described by Boyd (1979). The temperature ranged between 25~'C - 27.5~'C (mean = ~c 26.31~'C), while pH ranges between 6.3 and 7.5(mean = ~c 6.89). The highest value obtained for alkalinity was I5.4mg L-1, while the lowest was 4mgL-1(mean = ~c 10.2mg L-1). Dissolved oxygen concentration value was between 4.lmgL-1, and 8.6mgL-1(mean = ~c 6.35mgL-1), the turbidity in dry season range between 50 to 60 cm and in rainy season, it ranged between 4 to 7 cm. The total dissolved substances range between 40ppm and 200ppm. The conductivity value ranged between 80~ks/cm and 400~ks/cm. An extreme high concentration of phosphate was recorded and ranged between 0.9mL-1 and 4.2mg L-1, which was due to water and land use practice. The nitrate concentration was negligibly low with concentration between 0.00% and 0.15%. This concentration was however adequate and support fish population and freshwater snails such as Melanoides tuberculata