Burrow Morphological Characteristics of Soldier Crab (Dotilla myctiroides) on the Libong Island, Koh Libong Subdistrict, Kantang District, Trang Province, Thailand

Dotilla myctiroides, the soldier crab, digs burrows in sand flats and extracts nutrients from sediment. The present study investigated the burrow morphology of this soldier crab, at Laem Juhoi Beach, Libong Island, Koh Libong Subdistrict, Kantang District, Trang Province, Thailand. Randomly selected burrows were examined by injecting molten paraffin into them. The crab found inside a burrow was collected and measured for its carapace length. The shapes of the complete burrow casts were identified, and various morphological characteristics of the burrow casts were recorded. A total of 84 burrows were identified, all of them were the I-shaped or single-tube burrows. The burrows were categorized into two groups based on the burrow opening diameter: the <12 mm group and the ≥12 mm group. The burrow opening diameter ranged from 7.50 to 20.10 mm while the end diameter at the burrow bottom ranged from 8.40 to 21.00 mm, and the total length of the burrows ranged from 27 to 206 mm. The carapace length showed a significant correlation (p<0.05) with the burrow opening diameter in both groups. Additionally, the burrow opening with a diameter <12 mm group had significantly greater hole distances than the burrow opening with a diameter ≥12 mm group (p<0.05). The observed variations in hole distances suggest potential differences in ecological and behavioral factors that influence the burrow morphology of D. myctiroides in distinct size categories.