Length-weight relationships and condition factor of the sea urchin Echinometra mathaei (Echinoidea: Echinodermata) on Buleji rocky shore of Karachi, Pakistan
The length frequency, length-weight relationships and variation in condition factor was studied in the population of Echinometra mathaei (Blainville, 1825) found on the rocky shore of Buleji, Karachi, Pakistan during the period from April 2011 to November 2012. The test diameter (length) in E. mathaei ranged from 19.0 and 77.2 mm with mean test diameter of 46.6 ± 6.3 mm. The modal size-class in the population of this species was 41-50 mm. The total wet weight ranged from 13.3 to 121.6 g with a mean of 50.1 ± 18.3 g and showed the modal size class of weight to be 31–40 g. Sex-wise and season-wise length weight relationship (LWR) showed negative allometric growth trend (b not equal to 3, P < 0.001). The condition factor (Kn) estimated for E. mathaei ranged between 0.95 to 1.06 in males, 0.99 to 1.04 in females and 0.98 to 1.02 in pooled sex at Buleji. Analysis of variance indicated that there is statistically no significant difference between the mean of the Kn values for pooled sex in 14 months (ANOVA, F = 0.332; P > 0.05). However, analysis of variance showed a significant difference between the Kn values in different seasons at Buleji (ANOVA, F = 59.57; P < 0.05).
| Main Authors: | , |
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| Format: | article biblioteca |
| Language: | English |
| Published: |
2016
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| Subjects: | Biology, Length-weight relationship, condition factor, Echinometra mathaei, rocky shore, Karachi, |
| Online Access: | http://hdl.handle.net/1834/40811 |
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| Summary: | The length frequency, length-weight relationships and variation in condition factor was studied in the population of Echinometra mathaei (Blainville, 1825) found on the rocky shore of Buleji, Karachi, Pakistan during the period from April 2011 to November 2012. The test diameter (length) in E. mathaei ranged from 19.0 and 77.2 mm with mean test diameter of 46.6 ± 6.3 mm. The modal size-class in the population of this species was 41-50 mm. The total wet weight ranged from 13.3 to 121.6 g with a mean of 50.1 ± 18.3 g and showed the modal size class of weight to be 31–40 g. Sex-wise and season-wise length weight relationship (LWR) showed negative allometric growth trend (b not equal to 3, P < 0.001). The condition factor (Kn) estimated for E. mathaei ranged between 0.95 to 1.06 in males, 0.99 to 1.04 in females and 0.98 to 1.02 in pooled sex at Buleji. Analysis of variance indicated that there is statistically no significant difference between the mean of the Kn values for pooled sex in 14 months (ANOVA, F = 0.332; P > 0.05). However, analysis of variance showed a significant difference between the Kn values in different seasons at Buleji (ANOVA, F = 59.57; P < 0.05). |
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