Journal of the Marine Biological Association of India

Morphological and molecular characterisation of eggs and larvae of dark sleeper goby, Butis humeralis (Valenciennes, 1837), collected from a tropical estuary

Volume 68 Issue 1

M. K. Shameena, V. L. Sruthy, R. Ratheesh Kumar, K. A. Sajeela and P. Kaladharan

doi:10.6024/jmbai.2026.68.1.2668-01

Abstract

Eggs of Butis humeralis (Valenciennes, 1837) were described for the first time from the west coast of India. A cluster of sparsely distributed eggs of B. humeralis was observed on a gritted glass panel submerged for biofouling studies in the Cochin estuary, Kerala. The egg mass covered an area of 62 cm2 with an average abundance of 120 ± 30 eggs/cm2. Molecular characterisation of the egg was performed to confirm species identification. The brownish-yellow, sticky, pyriform-shaped, transparent eggs of B. humeralis measured 0.41 ± 0.01 mm in diameter along the long axis and 0.36 ± 0.01 mm along the short axis. The newly hatched larvae of B. humeralis were slender and translucent with a total length of 1.01 ± 0.037 mm. The total length of the preflexion larvae was 2.08–2.12 mm. DNA barcoding using partial mitochondrial cytochrome oxidase subunit I gene sequences confirmed species identity, with 100% similarity to B. humeralis sequences from the Cochin estuary, which were deposited in GenBank. Genetic divergence analysis showed extremely low intraspecific variability (0.0%) and moderate interspecific divergence (5.7–24.7%), confirming genetic distinctness and clear taxonomic separation of B. humeralis. The first taxonomic description of the early life stages of this lesser-known species will facilitate future
ichthyoplankton identification and contribute to assessing its conservation status within the ecosystem. 

Keywords

Goby, Cochin estuary, eggs, larvae, DNA barcoding

Date : 26-05-2026