Growth and reproduction of palaemonid shrimp palaemon concinnus and Morphometric Differentiation of the sesarmid crab perisesarma guttatum in selected Mangroves along the Coast of Tanzania
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Date
2009
Authors
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Journal ISSN
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Publisher
University of Dar es Salaam
Abstract
Population structure and reproductive potential of Palaemon concinnus in Ruvuma estuary and the application of geometric rnorphometrics techniques to differentiate the carapace shape of Perisesarma guttatum for assessing connectivity for populations found in Dar es Salaam and those in Mtwara were studied . Samples of P. concinnus were collected on a monthly basis from May 2006 to April 2007 and once for P. guttatum. Sample werepreserved in 70% ethanol. P.concinnus individuals were sorted into ovigerous.,non-ovigerous and sexed. The carapace length and body weight were measured and embryo developmental stage examined prior to counting the eggs. The carapace for each sex of P. guttatum was photographed and the file utility program Tps was used to record landmarks followed by a series of analysis. The carapace length and bod) ,eight of P. concinnus ranged from 1.71 mm to 9.18 mm and 15.8 mg to 401.3 mg respectively. The slopes (b-values) of the carapace length-body weight relationship for males (2.42), females (2.64) and combined sexes (2.56) were significantly different from the isometric value (b = 3) hence negative allometric growth. Sex ratio was found to be 0.78: 1 (male: female) and significantly different from 1:1 ratio Cx2 = 40.611 , p < 0.001). Fecundity ranged from 34 to 312 eggs and correlated positively with carapace length (p < 0.0001). The carapace shape of P. guttatum in females and males was found to be significantly different in both sites and stations (p < 0.001). However some stations from the two sites did not show differences indicating possible connectivity of the gene pool.
Description
Available in print form, East Africana Collection, Dr.Wilbert Chagula Library, class mark (THS EAF QL444.M33M33)
Keywords
Decapoda, Shrimps, Lobsters, Crabs
Citation
Mahenge, J (2009) Growth and reproduction of palaemonid shrimp palaemon concinnus and Morphometric Differentiation of the sesarmid crab perisesarma guttatum in selected Mangroves along the Coast of Tanzania, Masters dissertation, University of Dar es Salaam, Dar es Salaam.