Morphological and molecular characterization of Haematomyzus elephantis (Phthiraptera: Rhynchophthirina) and Cobboldia elephantis (Diptera: Oestridae) in Asian elephants (Elephas maximus) from southern India

Highlights:

• First molecular characterization of H. elephantis and C. elephantis from India.
• Integrated morphological and COI-based molecular identification of elephant parasites.
• Detailed morphological documentation of lice and bot fly larvae in Asian elephants.
• Phylogenetic analysis confirmed species identity using reference GenBank sequences

The present study reports the occurrence, morphological characterization and molecular confirmation of Haematomyzus elephantis Piaget, 1869 and Cobboldia elephantis Steel, 1878 in Asian elephants (Elephas maximus) from Theppakadu Elephant Camp, Mudumalai Tiger Reserve, Tamil Nadu, India. During routine health screening in May 2024, 26 elephants were examined, with two found infested with lice and three exhibiting stomach bot fly larvae in faecal samples. Morphological examination of Haematomyzus elephantis lice revealed an elongated, oval body with a dark, chitinized dorsum, specialized rostrum, segmented antennae, robust tarsal claws and characteristic genital structures. Larvae of C. elephantis were identified based on segmented body, cephalo-pharyngeal skeleton, oral hooks, and posterior spiracles with longitudinal stigmal slits. Molecular analysis targeting the mitochondrial cytochrome c oxidase subunit I (COI) gene using species-specific primers confirmed Haematomyzus elephantis (218 bp) and C. elephantis (245 bp). Sequencing and phylogenetic analysis demonstrated 100% identity with reference sequences in GenBank, validating species identity and highlighting evolutionary divergence from related taxa. These findings provide novel morphological, molecular and phylogenetic data, contributing to the limited knowledge of parasitic infestations in Asian elephants and informing health monitoring and management strategies for both captive and wild populations.