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Impacts of Grazing by Milkfish (Chanos chanos Forsskal) on Periphyton Growth and its Nutritional Quality in Inland Saline Ground Water : Fish Growth and Pond Ecology
Issue:
Volume 1, Issue 3, December 2016
Pages:
41-52
Received:
12 September 2016
Accepted:
29 September 2016
Published:
3 November 2016
DOI:
10.11648/j.eeb.20160103.11
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Abstract: Two experiments (I and II) each under three different salinity levels (10, 15 and 20 ppt) were conducted to investigate the effects of addition of milkfish and substrate for periphyton development and its nutitional quality. Efforts were also made to investigate the hydrobiological parameters and growth of milkfish. Both experiments were run simultaneously with the difference that in experiment I, ponds were stocked with milkfish, while no fish were stocked in experiment II. No significant differences were observed in TDS levels among the three salinity treatments. Studies have revealed higher values of productivity indicating parameters (Alkalinity, NPP and GPP) under grazed conditions in comparison with the ungrazed conditions. A comparison of physico-chemical characteristics of pond water in between the two experiments (I and II) indicated not many variations. All parameters followed a trend similar to the ponds stocked with milkfish, except that BOD5 values were slightly higher and DO levels were slightly lower under ungrazed conditions. SO4 and o-PO4 levels were similar in both the trials. Addition of fish only slightly affected inorganic N-species (NO3N, NO2N), however, NH4N levels were significantly (P<0.05) low, while Alkalinity and total Kjeldahl nitrogen were significantly (P<0.05) high in treatment with fish at 15 ppt salinity. Irrespective of the water salinity, mean periphyton density scraped from the substrate increased with an increase in depth upto 50 cm in both the trials. A comparison of periphyton production/biomass and its pigment concentrations indicated significantly (P<0.05) higher values for dry matter, ash free dry matter (AFDM), ash, ash % of dry matter, algal constitutes, autotrophic index in ponds with fish (grazed conditions). On the other hand, periphyton number (units cm-2), total pigment concentration, chlorophyll a and pheophytin a remained significantly (P<0.05) higher in ponds without fish (ungrazed conditions). Results have also revealed a significant effect of salinity on fish growth with significantly (P<0.05) higher growth occurring in ponds maintained at 15 ppt salinity. Fish carcass protein, fat and phosphorus, VSI and HSI values also coincided well with highest fish growth at 15 ppt salinity. Proximate composition of periphyton had revealed significantly (P<0.05) higher nutritive value of samples obtained from ponds without fish.
Abstract: Two experiments (I and II) each under three different salinity levels (10, 15 and 20 ppt) were conducted to investigate the effects of addition of milkfish and substrate for periphyton development and its nutitional quality. Efforts were also made to investigate the hydrobiological parameters and growth of milkfish. Both experiments were run simult...
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Quantitative Determination of Weed Occurrence on Upland Rice of Bambasi, Ethiopia
Assefa Gidesa,
Theodrose Tadesse,
Alemu Dabi
Issue:
Volume 1, Issue 3, December 2016
Pages:
53-56
Received:
6 October 2016
Accepted:
20 October 2016
Published:
16 November 2016
DOI:
10.11648/j.eeb.20160103.12
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Abstract: The weed survey was carried out in 2012 and 2013 cropping season on eight to ten upland rice farmers’ fields respectively in Bambasi, Ethiopia to determine weed prevalence, species composition and distribution. A quadrant size of 0.25 m2 were used in a systematic sampling technique and a total of 21 weed species belonging to 12 families were identified and counted. The most dominant weed family based on the number of species recorded was poaceae (grasses) which comprized 5 species. during both cropping season survey, most (66.67 %) of the species were broad leaved herbaceous plant. weed species composition was analyzed using quantitative means and most frequent weed species in upland rice field during 2012 cropping season was cyprus rotondus (100%) followed by Ageranthum conizoid, Commelina subulata, Digitaria abisynica, Elusin indica and Leucas martinicensis. The dominance range during this year was 0.09 to 54.59% and Ageranthum conizoid accounted 54.59% of the species which was followed by Cyprus rotondus, Spergula arvensis and Commelina subulata. during 2013 cropping season Ageranthum conizoid and Polygonum nepalense were the most frequently (100%) occurred weed species followed by Cyprus rotondus, Commelina subulata, Digitaria scalarum, Elusina indica, Galensoga parviflora. The dominant weed species during this year (2013) was Polygonum nepalense (20%) followed by Ageranthum conizoid and Cyprus rotondus, Commelina subulata and Leucas martinicensis dominance level range between 16.36% and 4.02% respectively. The prevalence and density of most species on upland rice during 2012 and 2013 cropping season was similar. Moreover, similarity index between the 2012 and 2013 surveys were higher (100%). Thus, the weed control and management research strategy should consider the dominant and frequent weed species of both cropping seasons and weed flora composition.
Abstract: The weed survey was carried out in 2012 and 2013 cropping season on eight to ten upland rice farmers’ fields respectively in Bambasi, Ethiopia to determine weed prevalence, species composition and distribution. A quadrant size of 0.25 m2 were used in a systematic sampling technique and a total of 21 weed species belonging to 12 families were identi...
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Aneuploidy Occurrence in Oligochaeta
Tomáš Pavlíček,
Tova Cohen,
Shweta Yadav,
Michèle Glasstetter,
Petr Král,
Oren Pearlson
Issue:
Volume 1, Issue 3, December 2016
Pages:
57-63
Received:
2 August 2016
Accepted:
8 November 2016
Published:
2 December 2016
DOI:
10.11648/j.eeb.20160103.13
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Abstract: Appearance of aneuploidy in the germ and somatic lines is usually associated with chromosome and genome rearrangements leading to polysomies and cancer. However, aneuploidy plays an important role in chromosome evolution and in the regulation of the ontogenetic development and phenotypic expression. The latter is known as chromosome diminutions. In Oligochaeta (mainly family Naididae but also Lumbricidae, Erpobdellidae and Branchiobdellidae), we have equated the variability of the chromosome count numbers with aneuploidy based on the results of our analyses and identified chromosome-like nondisjunctions as a major mechanism responsible for it. Another author detected Robertsonian-like translocations producing aneuploidy in Eisenia fetida (Lumbricidae, Oligochaeta). Our observations, nevertheless, show that, among karyotyped haploid/diploid cells, the most frequent were haploid (1n) or diploid (2n) chromosome counts connected by multiples. The number of aneuploidy counts was decreasing with the increase of x in expressions 1n + x/1n – x or 2n + x/2n – x. Noteworthy is that not all frequencies of chromosomes in a pair have the same probability. For example, odd aneuploidy numbers of chromosomes are significantly less frequent than the even ones. The wide spread of aneuploidy among Oligochaeta supports the punctuated equilibria model of evolution.
Abstract: Appearance of aneuploidy in the germ and somatic lines is usually associated with chromosome and genome rearrangements leading to polysomies and cancer. However, aneuploidy plays an important role in chromosome evolution and in the regulation of the ontogenetic development and phenotypic expression. The latter is known as chromosome diminutions. In...
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Antipredator Mechanism of Hylarana nigrovittata (Blyth, 1856) (Anura: Ranide) from Kedah, Peninsular Malaysia
Issue:
Volume 1, Issue 3, December 2016
Pages:
64-67
Received:
18 October 2016
Accepted:
8 November 2016
Published:
12 December 2016
DOI:
10.11648/j.eeb.20160103.14
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Abstract: In this study, Hylarana nigrovittata was used as specimen organism to explore antipredator behaviour. In March 2016, five adult males of H. nigrovittata were collected from its natural habitat at Lata Bayu, Baling, Kedah, Peninsular Malaysia. When these specimens released in an open area, they leaped in various directions and showed several defensive mechanisms. Active escape is the main strategy and observed in all the specimens. Death feigning behaviour was shown by specimen 1 and 4, crouching down by specimen 3 and stiff-legged by specimen 4. However, specimen 2 and 5 hasn’t shown any defensive strategy except the active escape. These findings revealed the antipredator mechanism developed by H. nigrovittata, for a protection against the potential predators.
Abstract: In this study, Hylarana nigrovittata was used as specimen organism to explore antipredator behaviour. In March 2016, five adult males of H. nigrovittata were collected from its natural habitat at Lata Bayu, Baling, Kedah, Peninsular Malaysia. When these specimens released in an open area, they leaped in various directions and showed several defensi...
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Agricultural Drainage Water as a Source of Water for Fish Farming in Egypt
Magdy Soltan,
Mohamed Hassaan,
Fayza Abaas,
Abdel-Rahman Khattaby
Issue:
Volume 1, Issue 3, December 2016
Pages:
68-75
Received:
27 August 2016
Accepted:
12 November 2016
Published:
23 December 2016
DOI:
10.11648/j.eeb.20160103.15
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Abstract: In Egypt, the reuse of agricultural drainage increases the country’s available water resources by 20%. The aim of this study was to assess the impact of agricultural drainage water on accumulation of heavy metals and pesticide residues of Nile tilapia (Oreochromis niloticus) reared in earthen ponds. Six earthen ponds (2 hectare for each) in two fish farms located at the same area (3 ponds for each farm). The first pond group irrigated by fresh irrigation water (IW) and the 2nd group (in another fish farm) supplied by agricultural drainage water (ADW). Each pond was stocked with 40000 fish (2.22±0.1 g) and fed on 25% CP diet at a daily rate of 3% of the total fish biomass. At the experiment end (7 months) results showed that, physico-chemical parameters for IW and ADW remained in the favorable range for Nile tilapia growth. ADW had higher density of phytoplankton and zooplankton in comparison to IW. Accumulation of heavy metals in liver and gills were higher than in muscles and ranked as liver>gills>muscles. Iron had the highest concentration values of metals content in liver, gills and muscles of fish reared in two water types and the sequence of metals was as follows: Fe>Zn>Cu>Mn>Pb. All pesticides residues under permeable limits in fish reared in the two types of water. Fish reared in agricultural drainage water showed the lowest significant (P<0.05) red blood cells (RBCs), haemoglobin (Hb), hematocrit and (Ht) total protein and the opposite trend was recorded for glucose and amino transferases, AST and ALT. ADW ponds produced the highest significant body weight, weight gain specific growth rate and fish yield compared to IW.
Abstract: In Egypt, the reuse of agricultural drainage increases the country’s available water resources by 20%. The aim of this study was to assess the impact of agricultural drainage water on accumulation of heavy metals and pesticide residues of Nile tilapia (Oreochromis niloticus) reared in earthen ponds. Six earthen ponds (2 hectare for each) in two fis...
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