Gastropod Diversity at Azheekkal, Kollam, Kerala, India: A Historical Baseline from August–November 2017

Motivation: Historical biodiversity records provide useful reference points for coastal biodiversity monitoring, particularly in areas subject to continuing human use. Azheekkal, Kollam, Kerala, supports a diverse molluscan fauna, but historical records of its gastropod assemblage remain limited. Objectives: This study documents the gastropod assemblage recorded at Azheekkal during August–November 2017 and provides a historical reference dataset for future biodiversity assessments. Methods and Findings: Gastropods were collected monthly by hand from the shore and using fishing nets at different depths recorded in fathoms. A total of 125 specimens representing 19 taxa were recorded. Monthly abundance ranged from 19 specimens in October to 41 in August. Babylonia spirata was the most abundant taxon (24 specimens), followed by Oliveragemmula diomedea (21 specimens). Taxon richness ranged from 4 taxa in September to 12 in August. Shannon–Wiener diversity ranged from 0.992 to 2.047 among months and was 2.463 for the pooled dataset. These diversity indices were calculated for the present study from the original 2017 abundance records. Limitations: Sampling effort was not standardized, observations covered only four months with one visit per month, and environmental variables were not recorded. Therefore, monthly differences cannot be interpreted as seasonal patterns or as a current assessment of the assemblage. Conclusion: The 2017 observations provide a documented historical reference for the gastropod assemblage at Azheekkal. Standardized, replicated, year-round surveys incorporating environmental measurements and updated taxonomic verification are needed to evaluate contemporary diversity and longer-term changes.