Kentucky State University
Comparison of Morphotype Percentages of Three Different Genetic Strains of the Freshwater Prawn (Macrobrachium rosenbergii) Raised in Ponds in Kentucky
Institution
Kentucky State University
Faculty Advisor/ Mentor
Shawn Coyle; James Tidwell; Leigh Anne Bright
Abstract
We compared morphotype percentages of the total population for three different genetic strains of freshwater prawns reared under practical pond grow-out conditions in Kentucky. A random sample of >300 individuals per pond were classified into either one of three male morphotypes or one of two female morphotypes and individually weighed. The only significant difference (P<0.05) among average weights was in virgin females, with the Texas and Hawaii strains (32g and 31g, respectively) larger than the Myanmar strain (23g). A greater percentage of blue claws were found in the Texas strain (1.7%) than in the Hawaii strain (1.1%) and no blue claws were recorded for the Myanmar strain. The percentage of orange claw males (>20 g) was statistically similar for Texas and Hawaii (36%) and both were greater than the Myanmar strain (12%). The percentage of the small male morphotype (<20g) was statistically similar between treatments and averaged 17.2% overall. The percentage of reproductive females was similar between strain treatments and averaged 3.6%. The percentage of virgin females was greater for the Myanmar strain (62.4%) than for either the Texas or Hawaii strains, which were not different from each other and averaged 42.4% overall. The greater number of large morphotypes (i.e., blue claws, orange claws and reproductive females) in Texas and Hawaii strains largely accounts for production differences (total kg/ha) which were 183% and 161% greater, respectively than Myanmar prawns.
Comparison of Morphotype Percentages of Three Different Genetic Strains of the Freshwater Prawn (Macrobrachium rosenbergii) Raised in Ponds in Kentucky
We compared morphotype percentages of the total population for three different genetic strains of freshwater prawns reared under practical pond grow-out conditions in Kentucky. A random sample of >300 individuals per pond were classified into either one of three male morphotypes or one of two female morphotypes and individually weighed. The only significant difference (P<0.05) among average weights was in virgin females, with the Texas and Hawaii strains (32g and 31g, respectively) larger than the Myanmar strain (23g). A greater percentage of blue claws were found in the Texas strain (1.7%) than in the Hawaii strain (1.1%) and no blue claws were recorded for the Myanmar strain. The percentage of orange claw males (>20 g) was statistically similar for Texas and Hawaii (36%) and both were greater than the Myanmar strain (12%). The percentage of the small male morphotype (<20g) was statistically similar between treatments and averaged 17.2% overall. The percentage of reproductive females was similar between strain treatments and averaged 3.6%. The percentage of virgin females was greater for the Myanmar strain (62.4%) than for either the Texas or Hawaii strains, which were not different from each other and averaged 42.4% overall. The greater number of large morphotypes (i.e., blue claws, orange claws and reproductive females) in Texas and Hawaii strains largely accounts for production differences (total kg/ha) which were 183% and 161% greater, respectively than Myanmar prawns.