Length-weight relationship and the diets of Clarias lazera (Cuvier and Valenciennes), family Clariidae (Osteichthyes: Siluriformes) in Zaria, Nigeria

The length-weight relationship and the diets of Clarias lazera were investigated between July 1981 and June 1982. About 450 specimens were examined. The standard lengths of the fish ranged from 8.5 cm to 42.2 cm. Significant differences were found between the standard lengths of the males and females with the latter slightly shorter. Somatic weights varied between 10 g to 502 g. Length-weight regression analysis gave a "b" value of 3.02 for both males and females combined; thus indicating an isometric growth. Analysis of the food in the stomachs showed that the fish is an omnivore although, it fed more on insects and fish than other food items

Triploidy induction in Heterobranchus longifilis (Family: Clariidae) by cold shock

Triploid was induced in African Catfish (Heterobranchus longifilis) by cold shocking activated eggs at 5 degree C for forty minutes starting 3-4 minutes after fertilization. Triploidy was confirmed from mitotic chromosomes prepared from embryo which showed 100% triploidy in the cold shocking treatment and 100% diploidy in the control treatment

Effects of some environmental factors on the fecundity of Tilapia species (Family Cichlidae) in Kigera Reservoir, New Bussa

The effects of some environmental factors on the fecundity of Tilapia species (Family Cichilidae) was carried out at the Kigera dam. Four Tilapia species caught were Tilapia zilli, Hemichromis fasciatus, Sarotherodon galilaeus and Oreochromis niloticus while the environmental factors considered were water temperature, Dissolved Oxygen, pH value, level of rainfall and rate of sunshine and range of time. 43 fish comprising of 25 male with (58.1%) and 18 females having (41.9%) were studied with 74.42% been sexually matured. Both high levels of rainfall and dissolved oxygen favoured fecundity. The spawning peak occurred in (July), environmental factors monitored indicated that dissolved oxygen ranges from 3.7 to 4.45mg/lit rainfall ranges from (34.90mm to 237.80mm) sunshine ranges from (5hrs-8hrs) and pH ranges from (7.35-7.45). The spawning of these species in their natural or hatchery condition is therefore best achieved during the peak of raining season

The identification of British adult specimens of Sigara lateralis (Leach), Sigara concinna (Fieber), Callicorixa praeusta (Fieber) and Callicorixa wollastoni (Douglas & Scott) (Hemiptera Heteroptera: Corixidae)

The aim of this communication is to briefly review nomenclature in the genus Callicorixa, describe the variation in the dark markings on the posterior legs of all four species, describe alternative diagnostic features, and provide a key to identification based on these alternative features. Attention is also drawn to a small error in FBA Scientific Publication 50 (Adults of the British aquatic Hemiptera Heteroptera: a key with ecological notes).

Structure of the limbs and its significance for the ecology and systematics of the family Chydoridae. [Translation of: Voprosy Gidrobiologii, p385, 1965]

For an explanation of the dynamics of numbers of chydorids, appearing a massive group in the littoral of fresh water bodies, the structure of the limbs of 29 species was studied.

Key to the larvae of the genera of the sub-family Orthocladiinae from Larvae and Pupae of midges of the sub-family Orthocladiinae of the fauna of the USSR. [Translation from: Larvae and pupae of midges of the subfamily Orthocladiinae of the fauna of the USSR (Diptera, Chironomidae = Tendipedidae) (ed. Pankratova V.Ya.), 51-55. Leningrad, Nauka, 1970. ]

A key to the larvae of the genera of the sub-family Orthocladiinae from Larvae and Pupae of midges of the sub-family Orthocladiinae. Parts of the key refer to the rest of the publication which is not included in this partial translation.

Family: Cladophora Kutzing 1843. identification key. [ Translation from: Flora Slodkowodna Polski 10, 227-263, 1972.]

A description of the algal genus Cladophora from Vol 10 of the ”Freshwater Flora of Poland”. Illustrations are included.

The family of chironomids or midges - Chironomidae. Keys to larvae and pupae [Translation from: Guide to the freshwater invertebrates of the European area of the USSR (Plankton and benthos) (ed. L. A. Kutikova and Ya. I. Starobogatov), p.371-431. Leningrad, Gidrometeoizdat, 1977]

The translation of this section of the larger publication ”Opredelitel' presnovodnykh bespozvonochnykh evropeiskoi chasti SSSR. (Plankton i bentos)” provides identification keys to the larvae and pupae of chironomids that occur in the Soviet Union. The morphology of the larvae of Chironomidae is described in the introductory part.

Report on the 1995 stock assessment of the Douglas catchment

The River Douglas has a long industrial heritage beginning in the early 18th century with its use by boats carrying goods between Wigan and Tarleton. The River and its tributaries have also historically been, and to a certain extent are still, subject to polluting inputs from the urban, agricultural and industrialised areas located within its catchment. During the early stages in the production of the River Douglas Catchment Management Plan, it became apparent that very little data existed on the populations of coarse and salmonid fish species within the River Douglas system. The data that did exist was largely anecdotal, consisting of catch reports from anglers or water bailiffs, or of dead and distressed fish following pollution incidents. This study was initiated to assess the status of coarse and salmonid fish species within the River Douglas system and so address the lack of knowledge. Eighty two sites were surveyed by electric fishing, including 14 sites using an electric fishing punt and up to four anodes. The data was analysed according to a new National Fisheries Classification Scheme. This classified the sites by the fish stock s present and compared the results with a database containing information from sites around the country that have similar habitat types. A stocking experiment was also undertaken in the River Lostock using chub reared at the Leyland Hatchery. These were marked with an identifiable blue spot in the spring of 1995 and then released into three, previously surveyed, locations in the river. These sites were then resurveyed during the summer stock assessment. This report also Site Reports with details on monitored sites, habitat features and fishery classification.

Development of larval and early juvenile penpoint gunnel (Apodichthys flavidus) (family: Pholidae)

The penpoint gunnel (Apodichthys flavidus) is a member of the perciform family Pholidae. Pholids, commonly referred to as gunnels, are eel-like fishes that inhabit the rocky intertidal and subtidal regions of the northern oceans and are often associated with macroalgae, such as Fucus spp. or kelp (Watson, 1996). Gunnels are ecologically important forage fishes that form part of the diet of birds and commercially important groundfish species (Hobson and Sealy, 1985; NMFS1; Golet et al., 2000). The diet of A. flavidus and other pholids comprises primarily harpactacoid copepods, gammarid amphipods, isopods, and other crustaceans (Cross, 1981). Apodichthys flavidus ranges along the west coast of North America from southern California to the Gulf of Alaska (Mecklenburg et al., 2002). Adult A. flavidus are distinguished from other pholids by their total vertebral counts, the presence of a thick and grooved first anal spine, a preanal length that is approximately 60% standard length (SL), and a dark green to light olive coloration (Yatsu, 1981). It is one of the largest pholids (up to 46 cm) and is important in the live fish trade for both home and public aquaria (Froese and Pauly2).

Length-weight relationships of five species of the family Sparidae in the Gulf of Guinea

Length-weight relationships are presented by sex and by country for five species of the family Sparidae (Pugrus caeruleostictus, Pagellus bellottii, Dentex canariensis, Dentex congonensis, Dentex angolensis) sampled in April 1990 during the Guinea '90 trawling survey off Sierra Leone, Liberia, Cote d'Ivoire and Ghana.

Comparative growth performance for species of the Family Clupeidae of Sierra Leone

Using length-frequency samples from the local fisheries and length-age data from otolith readings, von Bertalanffy growth parameters were estimated for the four species representing the Clupeidae family in Sierra Leone, Sardinella aurita, S. maderensis, Ethmalosa fimbriata and Ilisha africana showed the highest and lowest values of f, respectively, while Sardinella sp. were found to occupy the central position.

Recreational Fisheries in Biscayne National Park, Florida, 1976–19

Recreational creel survey data from 28,923 intercepts collected from Biscayne National Park, Florida and surrounding waters were analyzed for January 1976 through July 1991, prior to disruptions caused by Hurricane Andrew in 1992. A total of 261,268 fish and shellfish representing 170 species or higher taxa were recorded. The average trip landed 9.03 fish and/or shellfish. Mean annual landings per angler were 4.77 fish/angler/trip (from 3.8 in 1991 to 5.83 in 1981) and dropped significantly for each of the 2 years following Florida's adoption of mutiple new minimum size limits in 1985 and 1990. The relative contribution to total numerical landings by recreational party type were: skilled anglers (34.0%), food (19.8%), family (14.5%), novice (11.5%), spearfishing (10.3%), lobstering (9.6%), and other (0.3%). FIve species or higher taxa accounted for more than 50% of total landings by number: white grunt, Haemulon plumieri, 15.8%; spiny lobster, Panulirus argus, (10.6%; gray snapper, Lutjanus griseus, 10.6%; unidentified grunts, Haemulon spp., 7.3%; and dolphin, Coryphaena hippurus, 6.6%. An average of 4.39 fish or shellfish were reported released per trip. Five taxa accounted for 67% of all releases. Lobster divers reported the highest average release rate (5.73 per trip) and spearfishing the lowest (0.70 per trip). The ratio of releases to landings was 0.49:1 for all taxa, but ranged from 0.03:1 for dolphin to 1.19:1 for unidentified grunts. Spearfishing accounted for 12.0% of the total fishing trips sampled but only 10.3% of the total number organisms landed and 7.6% of all organisms caught. Hogfish, Lachnolaimus maximus, accounted for 49% if total spearfishing landings (13,286 of 27,015) and 84.3% of total 15,762 hogfish landed.