Viability of rearing swordtail, Xiphophorus helleri in Laguna De Bay with notes on its biology

Date

11-1996

Degree

Bachelor of Science in Biology

Major Course

Major in Cell Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Lourdes V. Castillo

Abstract

Production of freshwater aquarium fishes in the Philippines is largely a backyard industry. With the increasing demand in the world market today for aquarium fishes, it is envisioned to be the next dollar earner if production can be increased and sustained. Considering that the Philippines is endowed with several surface waters, this natural resource presents itself as an alternative medium that can be used to culture freshwater aquarium fishes. In this study, the viability of rearing in Laguna de Bay of the fish swordtail, a popular, live-bearing aquarium fish, was studied. Moreover, sonic aspects of its biology relevant to fish propagation was studied and described. Xiphophorus helleri reared in fish cages in the lake during the dry season (January to March) has better survival and growth than those reared during the wet season (June to September). Compared with pond reared swordtails, the growth rates (length and weight) were almost similar. Sexual maturity in pond reared female swordtails is attained earlier wherein 80% of the females were gravid on the 60th day whereas only 31% of lake reared females were gravid after 104 days. In males, elongation of the anal fin starts on the 42nd day to form the copulatory organ, the gonopodium. From observations of the weight and length of swordtails from the time they were born up to maturity stage, it was found out that pond cultured swordtails attain marketable size of 25.4 mm after the seventh week. The length and weight relationship is shown by the mathematical model: Log Weight = Log-4.78 1 3.17 Log Length. This relationship was derived through regression analysis. Moreover, the total number of eggs present per female is a function of length and weight: Log No. of Eggs = 0.785 Log Length + 0.115 Log Weight. With these mathematical models one can easily predict desired parameters. Xiphophoms helleri has numerous short an pointed cardifornt teeth adapted to herbivorous diet. Gill rakers arc short and unadorned, typical of an omnivorous species.The short stomach is connected to a very long, coiled intestine that is about twice its standard length. This structural modification gives the swordtail a longer time for digestion and provides more surface area for absorption of available nutrients Based on the results of this study, it is evident that the swordtails can be cultured in fish cages in Laguna de Bay and that its growth performance is almost similar to those reared in the pond. However, great care should be exercised during the wet season because of risks associated with typhoons. Post harvest techniques should also be developed because of ectoparasites.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

This document is currently not available here.

Share

COinS