Intersexual and spatial heterogeneity in trophic attributes of the sleeper, Bostrychus africanus (Eleotridae) in the Qua Iboe Estuary, Nigeria

There was variation in the ingestion of the food objects by the sexes. Despite the similarity in rank-order of the food objects, the ingestion of the objects vary significantly (rg=0.320, P>0.05). Dipterans adult and Hymenoptera were the only food objects not eaten by the males whereas insect remains and unidentified bivalves were absent from the trophics spectrum of the females. There was significant increase in feeding intensity by females than males. There was significant increase in GRI by specimens from Nipa Creek whereas individuals from mangrove creek recorded higher MGF and vice-versa. Dipterans adult. Hymenoptera, insect remains, Neritina glabrata and unid bivalves were absent from dietaries for nipa creek whereas a complete array of the food objects were eaten in the mangrove creek. The present findings highlights the importance of the mangrove ecosystem as the native vegetation encompassing great diversity of food resources and living conditions than the succeeding alien nipa vegetation

Food and feeding habits of Synodontis nigrita from the Osun River, SW Nigeria

An investigation was conducted into the food and feeding habits of Synodontis nigrita from the Osun River near Epe, Lagos, Nigeria. The food items in the stomach of the S. nigrita covered a wide spectrum, ranging from various types of plankton to invertebrates and plants. A seasonal variation was also noted in the stomach contents of S. nigrita over the period of investigation. The predominant food items found in the stomach were Polycystis spp., Closterium spp., Oedogonium spp., plant tissues, insect parts and detritus. This suggests that S. nigrita is an omnivore.

Limnology and fishery biology of the streams at Horton Plains, Sri Lanka (Ceylon)

The present study deals with the chemical, algal and faunal characteristics of the stream system at Horton Plains, the highest plains in Ceylon (altitude 2'225 m). The cultivation of seed potatoes and subsequent use of fertilizers have caused extensive silting and severe eutrophication of the stream systems. Since there are no indigenous fish, the trout Salmo gairdnerii has been introduced and it is the only fish found in these streams. The commonest fauna in the streams are crabs (Paratelphusa sp.), shrimps (Caridimr sp.), Simulium sp. and Chironomus sp. Their increase in number is probably correlated with increase in organic and detritus matter. The most important food items of the trout are the crabs living abundantly in the stream, insect larvae and terrestrial insects were also commonly found in the guts. Records of stocking and taking of trout in the Horton plains streams have shown that now less trout are taken relatively to the numbers stocked. This decrease may be possibly due to the eutrophication of the stream and also due to the possible use of pollutants in connection with the cultivation of seed potatoes.

Quality assessment of rotating and solar tunnel dried marine fish product

Studies were conducted to evaluate the quality aspects of marine dried fish i.e. silver jew fish (Johnius argentatus), Bombay duck (Harpodon nehereus) and ribbon fish (Trichiums haumela) products produced in rotating and solar tunnel dryers. On the basis of organoleptic characteristics such as colour, odour, texture, broken pieces, insect infestation and overall quality, four member panels of experts evaluated the quality of the dried products obtained from both rotating and solar tunnel dryers and all the products were found in acceptable quality. Reconstitutions properties of samples were in the range of 51.05 to 98.75% for the dried fish produced in rotating dryer, while 24.64 to 76.76% for dried fish produced in solar tunnel dryer. The highest reconstitution rate was found in dried silver jew fish and lowest in ribbon fish produced in rotating dryer. On the other hand, the highest reconstitution was observed in dried silver jew fish and lowest in dried Bombay duck produced in solar tunnel dryer. Proximate composition such as moisture, crude protein, lipid and ash content of the dried fish muscles produced in rotating dryer ranged from 16.36% to 19.1%, 62.35% to 67.37%, 6.37% to 10.75% and 7.00% to 8.05%, respectively and in solar tunnel dried fish products, they were in the range of 14.05% to 19.71%,57.64% to 69. 21%,6.92% to 15.40%and 7.69% to 8.80 %, respectively. The TVBN values of dried fish products obtained from rotating dryer were in the range of 15.02 to 19.05 mg/100g, while in solar tunnel dried fish products, the values were in the range of 15.46 to 19.21 mg/100g. The results of the studies indicated that dried fish produced from both rotating and solar tunnel drier were acceptable quality in terms of organoleptic and food quality aspects.

Panama City Fisheries Resources Office: FY 2004 Annual Report

HIGHLIGHTS FOR FY 2004 1. Completed the second of a 3-year Gulf sturgeon population estimate on the Escambia River, Florida. 2. Completed the first of a 2-year Gulf sturgeon population estimate on the Apalachicola River, Florida. 3. Conducted Gulf sturgeon presence-absence surveys in three other Florida river systems. 4. Documented Gulf sturgeon marine habitat use in the near shore waters of the Gulf of Mexico. 5. Identified environmental threats to Gulf sturgeon spawning habitat in the Choctawhatchee River, Florida. 6. Initiated a study to document Gulf sturgeon spawning with the collection of fertilized eggs in the Yellow River, Florida. 7. Implemented Gulf Striped Bass Restoration Plan by coordinating the 21st Annual Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system. 8. Over 86,000 Phase II Gulf striped bass were marked with sequential coded wire tags and stocked in Lake Seminole and the Apalachicola River. Post-stocking evaluations were conducted at 31 sites. 9. Drafted updates to Apalachicola-Chattahoochee-Flint Striped Bass Restoration and Evaluation Five-Year Plan with partners. 10. Fishery surveys were conducted on Tyndall Air Force Base and St. Marks and St. Vincent National Wildlife Refuges. 11. Habitat evaluations and population surveys were completed at 153 Okaloosa darter stream sites. 12. Aquatic insect biomonitoring and identification of over 39,000 individual aquatic macroinvertebrates was completed and provided to Eglin Air Force Base. 13. Ten years of fishery data from Okefenokee and Banks Lake National Wildlife Refuges was analyzed with recommendations incorporated into the refuge Comprehensive Conservation Plan. 14. A draft mussel sampling protocol was tested in wadeable streams in northwest Florida and southwest Georgia. 15. Implemented recovery plan and candidate conservation actions for 14 listed and candidate freshwater mussels in the Northeast Gulf Watersheds. 16. Worked with partners in developing the Spring Creek Watershed Partnership in the Flint River basin, Georgia. 17. Multiple stream restoration and watershed management projects were initiated or completed. A total of 6.8 stream miles were restored for stream fishes, along with 56.4 miles of coastline were enhanced for sea turtle lighting. A total of 135 acres of wetlands and 58 acres of understory habitat were restored. 18. Multiple outreach projects were completed to detail aquatic resources conservation needs and opportunities. Participated in National Fishing Week event, BASS ProShops event, several festivals, and school outreach.

Terrestrial ecosystem response to interdecadal climate variability in the western United States [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): We argue that the most important climatically-driven terrestrial ecosystem changes are concentrated in annual- to decadal-scale episodic events. These rapid ecosystem responses to climate change are manifested as regionally synchronized disturbance events (eg, floods, fires, and insect outbreaks) and increased drought-caused plant mortality rates.

Quality aspects of some exportable dried fishery products of Bangladesh

A study was conducted to evaluate the quality aspects of eight exportable dried fishery products of Bangladesh. The products were evaluated by examining organoleptic properties, water reconstitution behavior, microbiological and biochemical aspects. The water reconstitution rate was faster in ribbon fish and Bombay duck, and slower in other fishes and air bladder and shark fin products. Organoleptic and physical characteristics in respect of color, odor, texture, insect infestation and broken pieces of the products revealed that all of the products were either in excellent or acceptable condition. Total viable bacterial load ranged from 0.95 x 104 CFU/g to 1.8 x 104 CFU/g in dried products. Coliform bacteria was absent in all the dried fishery products. The results of moisture, crude protein, lipid and ash content of the products ranged from 16.20 to 23.51%, 58.37 to 82.86%, 0.17 to 14.44% and 0.58 to 9.23%, respectively. Non-protein nitrogen (NPN) contents were in the range of 0.104 to 2.372% and the pepsin digestibility values were of 88.41 to 94.23%. The results of the study suggested that the exportable dried products were of good quality and hygienically safe.

Prevention of infestation by Dermestes maculatus Degeer in east African dried fish by solar treatment

East African sun-dried fish infested by Dermestes maculatus were exposed to tropical sunlight at ambient temperature and analysed for insect mortality and weight losses. Solar treatment for 6 to 8 lo was highly effective for one layer of split sun-dried fish and 100% insect mortality was toted, while pest species were still present in the four layer batch. Weight losses between 1.2% and 10.2% were recorded, the top layer suffering the highest loss. The high surface temperature of 60°C caused fish to become brittle and quality losses occurred. A reduction in length of exposure/temperature is probably a presupposition for application of the method to local conditions.

The weevil-watermilfoil interaction at different spatial scales: what we know and what we need to know

The North American weevil ( Euhrychiopsis lecontei (Dietz)) is being considered as a biological control agent for Eurasian watermilfoil ( Myriophyllum spicatum L.). This native insect damages watermilfoil plants and is frequently associated with declining watermilfoil populations

Eurasian watermilfoil biomass associated with insect herbivores in New York

A study of aquatic plant biomass within Cayuga Lake, New York spans twelve years from 1987-1998. The exotic Eurasian watermilfoil ( Myriophyllum spicatum L.) decreased in the northwest end of the lake from 55% of the total biomass in 1987 to 0.4% in 1998 and within the southwest end from 50% in 1987 to 11% in 1998. Concurrent with the watermilfoil decline was the resurgence of native species of submersed macrophytes. During this time we recorded for the first time in Cayuga Lake two herbivorous insect species: the aquatic moth Acentria ephemerella , first observed in 1991, and the aquatic weevil Euhrychiopsis lecontei , first found in 1996 . Densities of Acentria in southwest Cayuga Lake averaged 1.04 individuals per apical meristem of Eurasian watermilfoil for the three-year period 1996-1998. These same meristems had Euhrychiopsis densities on average of only 0.02 individuals per apical meristem over the same three-year period. A comparison of herbivore densities and lake sizes from five lakes in 1997 shows that Acentria densities correlate positively with lake surface area and mean depth, while Euhrychiopsis densities correlate negatively with lake surface area and mean depth. In these five lakes, Acentria densities correlate negatively with percent composition and dry mass of watermilfoil. However, Euhrychiopsis densities correlate positively with percent composition and dry mass of watermilfoil. Finally, Acentria densities correlate negatively with Euhrychiopsis densities suggesting interspecific competition.

Panel Discussion - Management of Eurasian watermilfoil in the United States using native insects: State regulatory and management issues

While researchers have evaluated the potential of native insect herbivores to manage nonindigenous aquatic plant species such as Eurasian watermilfoil ( Myriophyllum spicatum L.), the practical matters of regulatory compliance and implementation have been neglected. A panel of aquatic nuisance species program managers from three state natural resource management agencies (Minnesota, Vermont and Washington) discussed their regulatory and policy concerns. In addition, one ecological consultant attempting to market one of the native insects to manage Eurasian watermilfoil added his perspective on the special challenges of distributing a native biological control agent for management of Eurasian watermilfoil.

Control of insect infestation in smoked West African sardines Sardinella maderensis 'Sawa' using actellic 50 EC solution

Fish which has been cured or are in the process of being cured by traditional methods are usually infested by insects, posing a real problem to traders and processors, especially in Nigeria. The effects of 0.03% actellic 50 EC solution and vegetable oil on insect infestion were studied using West African sardines, Sardinella maderensis. Actellic solution was more effective in combating insect infestation than vegetable oil. Appearance and perceived smoked fish flavour of fish treated with Actellic and vegetable oil differed (P<0.05), while taste was unaffected by treatment. Actellic 50 EC solution though effective, could be subject to abuse

Water mites: predators and parasites

The majority of water mites found in freshwater belong to the Hydrachnellae, a group which exhibit striking morphological diversity. This paper reviews work on the structure, morphology and taxonomy. The role of water mites as predators, their life history and their parasitic associations with aquatic insect or freshwater mollusc hosts is discussed along with the distribution of water mites in the British Isles.

A new technique to control insect infestation in Mas min

A process of heat treating Mas min at 125°C for 15 minutes and hermetically packing them up has been investigated. This method has been found to be successful in controlling insect infestation in Mas min. The Japanese method of packing Mas min in BHC coated containers has also been simultaneously examined and found successful under certain conditions. However, this process is found to impart slight undesirable flavors to the product. In addition, this chemical treatment is also likely to be more costly.