Journal of Animal Diversity

Journal of Animal Diversity

Morphological profile of the forelimb long bones and ribs in the Ganges River dolphin, Platanista gangetica (Lebeck, 1801) (Mammalia: Cetacea: Platanistidae)

Document Type : Original Article

Authors
Jannat Un Naim Tuli
Md. Manzoorul Kibria
Afia Khanam Beli
Shah Mohammad Kaisar
Jadab Kumar Biswas
Department of Zoology, Faculty of Biological Sciences, University of Chittagong, Chattogram-4331, Bangladesh
10.22034/JAD.2024.6.2.1
Abstract
We conducted a study on the morphology of the forelimb long bones and ribs in the Ganges River dolphin, Platanista gangetica (Lebeck, 1801) using traditional morphometric methods. A total of 17 morphometric measurements of six specimens of P. gangetica were taken. The humerus was the longest bone in the forelimb morphology, with its length ranging from 41.75 to 52.78 mm (mean: 45.57, SD: ± 5.07) in juveniles/subadults and 60.56 to 90.92 mm (mean: 76.75, SD: ± 22.90) in adults. The length of the scapula was 85.84 to 135.46 mm (mean: 102.18, SD: ± 23.00) in juveniles/subadults and 171.79 to 251.95 mm (mean: 211.87, SD: ± 56.68) in adults. Of 10 ribs, the sixth rib was the longest (mean: 133.55, SD: ± 24.12) in juveniles/subadults and the seventh (mean: 240.62, SD: ± 54.24) in adults. All measurements (except the two variables of the scapula) were significantly correlated (P < 0.05) with specific bone length. The allometric coefficients of all correlated variables of the humerus, radius, ulna, scapula, and the depths of ribs exhibited isometry against the length of the particular bone, respectively. We discussed the morphological patterns of the forelimb long bones and ribs in P. gangetica along with the structural and functional aspects of the aquatic lifestyles.
Keywords
Allometry
forelimb
Platanista gangetica
ribs
morphological pattern
Subjects
Journal of Animal Diversity
Volume 6, Issue 2 - Serial Number 2
Cover photo: Hamadruas sp. (Araneae: Oxyopidae), from Bannur, Dakshina Kannada district, Karnataka, India. Photo by Shraddha Kumari K, June 2020.
Spring 2024
Pages 1-10