Advances in Aquaculture and Fisheries Management

Advances in Aquaculture and Fisheries Management ISSN: 9424-2933 Vol. 8 (1), pp. 001-006, January, 2020. © International Scholars Journals

Full Length Research Paper

Effect of dietary carbohydrate to lipid ratios on growth, feed conversion, protein utilisation and body composition in climbing perch, ANABAS  TESTUDINEUS

M. Z. Ali*, M. Zaher, M. J. Alam and M. G. Hussain

Bangladesh Fisheries Research Institute, Freshwater Station, Mymensingh- 2201, Bangladesh, India.

Accepted 16 September, 2019

Abstract

An 8-week feeding trial was conducted in a static indoor rearing system with 15 cylindrical fibre glass tanks (80 cm diameter, 75 cm deep, 70-L each) to investigate the optimum carbohydrate to lipid ratio (CHO:L ratio) in climbing perch, ANABAS TESTUDINEUS (2.15 ± 0.07 g). Five isonitrogenous (40% crude protein) and isoenergetic (17.71 kJ g^-1 gross energy (GE)) fishmeal based diets with varying carbohydrate to lipid (CHO: L g/g) ratios of 0.58, 0.99, 1.53, 2.29 and 3.00 diets 1 to 5, respectively were tested. These diets had a fixed protein to energy ratio (P : E ratio) of 22.60-mg protein kJ^-1 GE. They were fed to triplicate groups of 50 fish at 5% body weight per day and the feed quantity was adjusted fortnightly. Diet 1, containing 11% carbohydrate and 17% lipid with a CHO: L ratio of 0.58 produced the poorest (P<0.05) growth rate, and feed and protein efficiency. Increasing dietary carbohydrate to 24%, concomitant with a reduction in lipid content to 10.50% that resulted in a CHO: L of 2.29 significantly improved (P<0.05) growth rate, and feed and protein efficiency. But, these did not differ from diets 2, 3 and 5, containing CHO:L ratios of 0.99, 1.53 and 3.00. Apparent net protein utilization (ANPU) in fish fed diet 5 was significantly higher (P<0.05) than those receiving diets 1 and 2, but did not differ from that of diets 3 and 4. Higher lipid deposition (P<0.05) in whole body was observed with decreasing dietary CHO: L ratios and increasing lipid levels. Whole body protein of fish fed varying CHO: L diets did not show any discernible variations among the dietary treatments. This study revealed that climbing perch, ANABAS TESTUDINEUS can perform equally well on diets containing carbohydrate ranging from 14.43 to 28.81%, with 9.60 to 14.64% lipid or CHO: L g/g ratios of 0.99 to 3.00.

Key words: Climbing perch, Anabas testudineus, carbohydrate to lipid ratio, protein utilization, dietary lipid, carbohydrate level.

Advances in Aquaculture and Fisheries Management ISSN: 9424-2933 Vol. 7 (7), pp. 001-014, July, 2019. © International Scholars Journals

Full Length Research Paper

Relationship and condition factors of abundant and commercial fish species of White Volta River, Ghana

*Emmanuel Gamal Vicker, Kwasi Quarshie and Micheal Dramani

Department of Fisheries and Aquatic Resources Management, University of Ghana, Legon, Ghana. *Corresponding Authors. E-mail: [email protected]

Accepted 25 June, 2015

Abstract

A study to assess the length-weight relationships and the condition factors of 3 abundant and commercial fish species namely Alestes baremoze, Brycinus nurse and Schilbe intermedius in the lower reaches of the White Volta River (Yapei) was conducted from October 2011 to March 2012. Using W = aLb, the length-weight relationships of the species were calculated. Condition factors of the species were obtained using the formula: W*100/Lb. A total of 284 A. baremoze were measured with total mid length size range of 10.5 to 44.5 cm. A total of 197 B. nurse were measured and ranged from 6.5 to 27.5 cm total mid-length whereas 175 of S. intermedius were measured and had total mid length size range of 8.5 to 26.5 cm. The slope b of the length-weight relationships of the 3 species were within the acceptable range of 2.5 to 3.5 and can be used to approximate the weight for the 3 species in the lower reaches of the White Volta River. The condition factors variation of A. baremoze and B. nurse showed a pronounced change in December 2011, when the surface water temperature was lowest. S. intermedius had no significant changes in the condition factors over the study period.

Key words: White Volta River, total mid-length, size range, species, surface water temperature.

Advances in Aquaculture and Fisheries Management ISSN: 9424-2933 Vol. 7 (6), pp. 001-005, June, 2019. © International Scholars Journals

Full Length Research Paper

Evaluation of the effect of temperature on egg development in an attempt to improve hatching success and fry production in Oreochromis karongae

*Lazarus T. Robert, Cassim S. Kambalu and Saulos Tiyambe

Department of Applied Limnology and Marine Sciences, Mzuzu University, Mzuzu, Malawi. *Corresponding Author. Email: [email protected]

Accepted 20 April, 2019

Abstract

A study was conducted to assess the effect of temperature on egg development in an attempt to improve hatching success and fry production in Oreochromis karongae. Temperature-dependent development rates and hatching period for fertilized eggs stripped from O. karongae, a mouth brooder, were determined in a recirculating system set up in a hatchery at the National Aquaculture Center, Domasi, Malawi. Three treatments namely; 25, 27 and 29˚C, were replicated thrice in 2-L Macdonald type incubation jars stocked with 265 fertilized stage 1 eggs of O. karongae, at water flow rate of 0.15 L/s. There was a curvilinear relationship between temperature and egg development, which was best described by a logarithm regression function. Hatching period decreased with increase in incubation temperature. The shortest hatching period was 7.3 days, which was observed at the highest incubation temperature (29°C) while the longest hatching period was 14.7 days, observed at the lowest temperature (25°C). Hatchability and fry survival were higher at higher temperatures. The study has, for the first time, ably described O. karongae egg development rates which suggest that increasing incubation temperature holds the potential to increase fry production, which is currently a bottleneck.

Key words: Oreochromis karongae, temperature-dependent, egg development rates, hatchability, survival, hatching period.

Advances in Aquaculture and Fisheries Management ISSN: 9424-2933 Vol. 7 (6), pp. 001-006, June, 2019. © International Scholars Journals

Full Length Research Paper

Analysis of the stomach content of African river prawn (Macrobrachium vollenhovenii) in Epe Lagoon, Nigeria

*Ambode Fredrick, Henry S. Bummi and Onoriose Patrick

Department of Applied Limnology and Marine Sciences, University of Lagos, Lagos, Nigeria.

Accepted 25 April, 2019

Abstract

The study investigated the stomach contents of Macrobrachium vollenhovenii from the commercial artisanal catches in Epe Lagoon in Lagos, southwest Nigeria from July to October 2008 and April to May 2009. The stomach analysis was carried out using frequency of occurrence and numeric methods. It was observed that the prawn fed on a variety of plankton species, which included chlorophyta, euglenophyta, xantophyta, chrysophyta, cladocera, copepoda, protozoa, dinoflagellate, diatoms, insect parts and unidentified food items, with chlorophyta and diatoms forming the most important food items. Chlorophyta constituted 32.00% by number and 83.62% by occurrence, diatoms constituted 31.55% by number and 65.09% by occurrence. Amongst the chlorophyta, Cosmarium granatum was the most preferred, constituting 7.93% by number and 17.67% by occurrence, followed by Ankistrodemus falcatus with 7.57% by number and 16.38% by occurrence, respectively. The least eaten food item was insect parts. The results indicated that M. vollenhovenii can be considered as an omnivorous detritivore.

Key words: Feeding habits, Macrobrachium vollenhovenii, Epe Lagoon.

Advances in Aquaculture and Fisheries Management ISSN: 9424-2933 Vol. 7 (5), pp. 001-010, May, 2019. © International Scholars Journals

Full Length Research Paper

Changes in fish species composition and their abundance in Lake Naivasha, Kenya

*¹Williams Kaimenyi, Eisha C. Karua¹ and James Kidero Ruto²

¹Department of Aquaculture and Fisheries Management, Jomo Kenyatta University of Agriculture and Technology, Kenya.

²Department of Applied Limnology and Marine Sciences, University of Nairobi, Nairobi, Kenya.

Accepted 15 March, 2019

Abstract

Changes in fish species composition and abundance in Lake Naivasha were investigated monthly for a period of 12 months. Data were obtained both from experimental surveys as well as commercial fish landings. The structure metrics considered included species abundance and composition, length-frequency and physico-chemical attributes. Results of the study showed that the fishery is currently dominated by the recently introduced common carp, Cyprinus carpio accounting for over 95% of the total fish landings, with the naturalized fish populations performing dismally both in terms of abundance as well as health conditions. The entry of the common carp into Lake Naivasha may have completely transformed the lake’s ecosystem integrity, driving the initially abundant tilapiine species to near local extinction. The study also confirms a restricted distribution of Micropterus salmoides to rocky-bottomed habitats of Hippo Point and Crescent Lake. Conversely, the long-fin barb, Barbus paludinosus, initially confined to the north swamp and the mouth of River Malewa, currently exhibits a lake-wide distribution. The changing climatic conditions as manifested in the lake level recessions may be a real threat to the fish stocks in the lake. Human activities in the catchment areas may also have contributed to the recent ecological changes witnessed in Lake Naivasha. This study proposes a number of recommendations with a view to ensuring ecosystem integrity and consequent sustainable fisheries of Lake Naivasha.

Key words: Ecosystem integrity, habitat preference, species introductions, sustainable fisheries, fish population, equatorial lake.