Aspects of biology of horseshoe crabs from Menggatal river and nearby coastal water, Sabah

Ng, Amelia Phei Fang (2009) Aspects of biology of horseshoe crabs from Menggatal river and nearby coastal water, Sabah. Universiti Malaysia Sabah. (Unpublished)

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Abstract

A study on horseshoe crab was conducted at Menggatal River and the nearby coastal water found three species, which were Carcinoscorpius rotundicauda, Tachypleus gigas, and Tachypleus tridentatus. Low catch per unit effort (12.4 individual/ha²) was recorded in Menggatal River. Ratio of C. rotundicauda males to female was 6.6: 1 reflects the imbalance population dynamic of the species in Menggatal River. Specimen collected were mature individuals of between 10 to 15 years old. Lengthy maturity period may result in any removal of matured individual to greatly impact the population. A tagging study found C. rotundicauda moving within a small range from the initial release site. It was also vulnerable to high rate of recapture especially in areas with high fishing activity. In Tanjung Aru and Teluk Likas, 4.8 % and 23.81 % of the tagged individuals were recaptured within 2 months respectively. Horseshoe crabs were found to prefer polychaetes worms to other food items which agreed to its benthic habitat. Based on these findings, it is suggested that anthropogenic causes were possibly the major reason for the decline in total population of species and imbalance sex ratio. Therefore, human activities such as fishing, dredging, reclamation and loss of coastal habitats would be highly detrimental to the population of horseshoe crabs

Item Type: Academic Exercise
Uncontrolled Keywords: A study on horseshoe crab was conducted at Menggatal River and the nearby coastal water found three species, which were Carcinoscorpius rotundicauda, Tachypleus gigas, and Tachypleus tridentatus. Low catch per unit effort (12.4 individual/ha²) was recorded in Menggatal River. Ratio of C. rotundicauda males to female was 6.6: 1 reflects the imbalance population dynamic of the species in Menggatal River. Specimen collected were mature individuals of between 10 to 15 years old. Lengthy maturity period may result in any removal of matured individual to greatly impact the population. A tagging study found C. rotundicauda moving within a small range from the initial release site. It was also vulnerable to high rate of recapture especially in areas with high fishing activity. In Tanjung Aru and Teluk Likas, 4.8 % and 23.81 % of the tagged individuals were recaptured within 2 months respectively. Horseshoe crabs were found to prefer polychaetes worms to other food items which agreed to its benthic habitat. Based on these findings, it is suggested that anthropogenic causes were possibly the major reason for the decline in total population of species and imbalance sex ratio. Therefore, human activities such as fishing, dredging, reclamation and loss of coastal habitats would be highly detrimental to the population Menggatal River, horseshoe crab, population, polychaetes worm, anthropogenic causes
Subjects: S Agriculture > SH Aquaculture. Fisheries. Angling
Q Science > QH Natural history > QH301 Biology
Divisions: SCHOOL > School of Science and Technology
Depositing User: MDM SITI AZIZAH IDRIS
Date Deposited: 25 Feb 2014 06:57
Last Modified: 12 Oct 2017 04:15
URI: http://eprints.ums.edu.my/id/eprint/8346

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