Status : Taken down
Personal Name Benjamin, Joanne Pearl Frances D.
Resource Title Geometric morphometrics and RAPD analysis in wild and hatchery milkfish (Chanos chanos Forsskål)
Date Issued January 2016
Abstract Milkfish (Chanos chanos Forsskål) is one of the leading fish in Philippine aquaculture. In this study, landmark-based geometric morphometrics (GM) and randomly amplified polymorphic DNA (RAPD) techniques were tested as rapid and inexpensive tools to discriminate milkfish from geographic populations. These markers were used to compare Philippine and Indonesian milkfish populations as well as wild and hatchery populations. This is to assess if there is a genetic advantage for importing fry from Indonesia under the assumption that fry from Indonesia are genetically better than Philippine milkfish. Thirty milkfish specimens were used from each of four hatchery Philippine populations: BFAR- Tiwi, Albay; BFAR-Calape, Bohol; BFAR-Benoni, Camiguin; and Iloilo (Hautea Hatchery) and one from Bali, Indonesia, obtained in Paombong, Bulacan (Valencia Hatchery). Philippine samples from the wild were collected from: BFAR-Antique; Camiguin wild and Sagñay, Camarines Sur while wild Indonesian samples include those from Medan and Sulawesi. In geometric morphometric analysis, one Philippine hatchery population from a private hatchery in Cebu (Oversea) and wild samples from Claveria and Sarangani were included. Results using both GM and RAPD indicate no genetic differentiation between Philippine and Indonesian samples as well as between wild and hatchery populations. Variation was found to occur mostly within the populations, suggesting that these milkfish
populations have high genetic variability. In RAPD analysis, Camiguin wild had the highest genetic variability (Nei’s gene diversity (h)=0.1733, percentage of polymorphic bands (PPB)=62.81%) followed by all Indonesian populations while BFAR-Bohol had the lowest (h=0.1320, PPB=42.98%). Both Camiguin populations also exhibited higher genetic similarity with Indonesian samples than with Philippine populations. Characteristic bands were observed in Medan (≈400 bp) as well as Sulawesi and Bali (≈1,100 bp). The lack of genetic segregation may be indicative of high gene flow and low genetic divergence of milkfish. Both the perception of milkfish growers in the Philippines that milkfish fry from Indonesia is genetically better than Philippine milkfish is not supported by results of the study. There is no need to import Indonesian fry if the only basis is genetic consideration as Philippine and Indonesian milkfish are genetically similar. Perhaps differences in growth from the two sources can be attributed to other factors such as environmental and milkfish culture practices. The lack of genetic differentiation between wild and hatchery milkfish also suggests that any population would be a good seed stock source. The study of genetic diversity and population structure are important in the conservation and management of milkfish.
Degree Course Master of Science in Biology
Language English
Keyword Chanos chanos Forsskal; Milkfish; Geometric Morphometrics (GM); Randomly Amplified Polymorphic DNA (RAPD)
Material Type Thesis/Dissertation