Seasonal distribution of benthic foraminifera at Nana Layja, Kachchh, Gujarat – India

Abstract

Benthic foraminiferal abundance from three sites at Nana Layja from the coast of Kachchh was studied over a period of one year to determine the seasonal variability. All the three sites were dominated by Ammonia beccarii (Brunnich, 1772), Pararotalia calcariformata (Le Calvez, 1949), Elphidium advenum (Haynes, 1973), Eponides repandus (Montfort, 1808) and Quinqueloculina bosciana (d'Orbigny, 1826). These showed considerable seasonal variability at the studied three sites. The maximum total foraminiferal abundance was found on December 2016 while the minimum was observed on June 2017. A. beccarii, P. calcariformata, and E. repandus exhibited a seasonal pattern similar to the total foraminiferal abundance. Whereas, E. advenum and Q. bosciana showed a different pattern of abundance with the minimum and maximum abundances found in December 2016 and June 2017, respectively. Other two rare species recorded were Spiroloculina sp. 1 (Alcide d'Orbigny, 1826) and Rosalina globularis (Alcide d'Orbigny, 1826) in all the seasons. Species diversity analysis showed that the three sites are rich in species variability with a high Shannon−Weiner Index and low Evenness Index. The physicochemical characterization of seawater collected from three sites showed distinct seasonal variations.