SDCA Student Research Journal

Abstract

In an aquatic environment where microorganisms are abundant, crustaceans that have lived here have developed an effective system for detecting and eliminating noxious microorganisms. The haemolymph serves as the fluid that circulates in the body of marine invertebrates, where nutrients, oxygen, hormones and cells are located. These fluids also have a biological process that may be similar to vertebrate antibodies, which may help activate their innate immune mechanisms and help to fight or clean pathogens that may infect them. This research aims to determine and compare the antimicrobial property of haemolymph extract from mantis shrimp (Oratosquilla oratoria) and mud crab (Scylla serrata) against Staphylococcus epidermidis and Pseudomonas aeruginosa. To begin with, mantis shrimps and crabs were collected from a local market in Cavite City, Cavite. For the extraction, the researchers collected the haemolymph of mantis shrimp (Orastosquilla oratoria) by suction from the pericardial sinus using sterile syringe and haemolymph from mud crab (Scylla serrata) was collected by cutting each walking leg of the animal with fine sterile scissors. The haemolymph was mixed with an anticoagulant solution [sodium citrate buffer, pH 4.6 (2:1, V/V)] to avoid degranulation and coagulation of the extract. Then, the samples were subjected to centrifugation at 10,000 RPM for 10 minutes at 4˚C to remove haemocytes from plasma, then supernatant was aspirated and stored at 4˚C until use. The antimicrobial activity of haemolymph from mantis shrimp and mud crab was assayed against Staphylococcus epidermidis and Pseudomonas aeruginosa using 10μl, 20μl, 30μl, and 40μl of the extract. Agar well diffusion method was used as the susceptibility method for testing the test organisms of interest.

Keywords: Haemolymph; Extraction; Mantis shrimp (Orastoqullia oratoria); Mud crab (Scylla serrata); Antimicrobial activity; Staphylococcus epidermis; Pseudomonas aeruginosa.