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Science, Marine and Environment

HORSESHOE CRAB, Tachypleus gigas NUMBER OF NESTS AND EGG COUNTS
ON SEDIMENTS WITH DIFFERENT GRAIN SIZE

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Amirah Nur Zahirah binti Abdullah , Faridah binti Mohamad *
Faculty of Science and Marine Environment, Universiti Malaysia Terengganu
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21030 Kuala Nerus, Terengganu, Malaysia.
*Corresponding author: mfaridah@umt.edu.my

This study investigated the effect of different grain sizes of the artificial spawning tank on
horseshoe crab, T. gigas by means of the number of nests and egg counts. Three
different grain sizes were used in this experiment which are coarse, medium and fine
STUDENT RESEARCH DAY 2021 were found in medium section and 3 nests found in fine section. No nest found in coarse STUDENT RESEARCH DAY 2021
grain size. The grain size was measured using dry sieving method and classify based on
Wentworth size class. A total of 13 nests were found during the observation. 10 nests

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section. From 13 nests found, only 7 nests contain T. gigas eggs. All the egg laid in
medium section and no egg found in fine grain size section. Number of eggs in each nest
were varied from 0-218. The highest number of eggs found in nest 4 which is (N= 218)
which they spent 8 minutes for spawning. The lowest number of eggs laid found in nest
5 which is (N=135) that they spent 6 minutes of spawning duration. This study prove that
there is significant difference between the number of nests and eggs in coarse sand,
medium sand and fine sand in spawning tank. Tachypleus gigas showed maximum
number of eggs in medium sand. The finding of this research suggest that medium grain
size is the best choice for artificial grounds for horseshoe crab, T. gigas. In future study,
the hatching rate of these laid eggs can be further investigated in laboratory.

Keyword: Egg, nest, grain size, Tachypleus gigas, horseshoe crab, spawning.

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