Morphometric and condition factor of tumid venus clam (Gafrarium tumidum, Roding 1798) in Lagonoy Gulf, Albay, Philippines

Abstract

This paper describes the length-weight relationship (LWR) and condition index (K) of the tumid venus clam Gafrarium tumidum collected off the coastal area along Lagonoy Gulf. Seven hundred individuals of G. tumidum were collected and subjected to various analyses. The results showed that the length and weight measures of the species have a strong relationship exist between them (R2=0.80-0.83). The growth pattern base on the computed slope (b) values showed allometry in both cases. Specifically, length measures (Shell height, SH and Shell width, SW) show negative allometry indicating that X (SW) is increasing relatively faster than Y (SH); whereas, Total weight (TW) vs. SH and SW shows positive allometry indicating that Y (TW) is increasing faster than X (SH and SW). The K value ranges in different length groups were 1.07 to 1.18, whereas the K value ranges from 0.95 to 1.43 in different weight classes. Condition index shows significant variation per class in relation to length and weight measures (P<0.05). The average value of K was 0.97 (±0.22) indicating a slightly slender body condition. Therefore, such findings could provide basic information on the biology of the species and be an essential basis for the development of a management scheme for this vulnerable resource.