Morphometric analysis and preliminary semi-quantitative expression analysis of two sardine (Sardinella) species in the Philippines

Date

6-2024

Academic Strand

Science, Technology, Engineering, and Mathematics (STEM) Strand

Adviser

Lea C. Garcia

Principal

Buela, Mabel S.

Abstract

Sardinella tawilis, which can only be found in the Philippines, was reported as an endangered species by the IUCN Red List in 2017. This rare freshwater sardine has a marine counterpart, the mophologically identical S. hualiensis. Distinction between the two species has an important role in their conservation, especially for S. tawilis. Because the two are closely alike, S. tawilis was inferred to have evolved from S. hualiensis due to geographical isolation. This study was conducted to identify the distinguishing characteristics between these two sardine species that emanate from their separate aquatic habitats. Hence, comparisons were done at both the morphological and genetic levels. Geometric (landmarks-based) morphometric analysis using Principal Component Analysis (PCA) showed the separation between S. tawilis and S. hualiensis, with PC1 (68%) accounting for the most notable variation between the landmarks that is tested as significantly different using one-way ANOVA (P<0.05). Traditional (measurement-based) morphometric analysis also revealed that the body (sd = 1.534) and anal fin (sd = 1.047) lengths influenced the distinction between the two Sardinellas, with S. Aualiensis having a slightly larger body size and shape. For the semi-quantitative transcriptomics approach, the relative densities of the clcnk gene in the kidney samples of the Sardinella species were considered. Through pairwise mean comparison, a significant difference in the clcnk expression levels between the sister species was established, in which the bands from S. hualiensis (* = 0.845) had a higher relative density than that from S. tavilis (i=0.29). This significant difference indicates how the two have evolved to adapt to their unique habitat. Additionally, the idea that the clenk gene plays a crucial role in the ecol ogical success of each species is supported. Overall, the research findings suggest that the freshwater S. tawilis differs from its saltwater sister species, S. hualiensis at the morphological and transcriptomic levels. This study serves as a stepping stone to future projects about the two Sardinella species. This is an internship under the pioneering program "Multi-omics Analyses Characterizing the Evolutionary Adaptation of the Endemic Philippine S. tawilis" focused on studying S. tawilis using omics technologies.

Language

English

LC Subject

Capstone

Location

UP Rural High School

Document Type

Capstone

This document is currently not available here.

Share

COinS