Seawater Shrimp Research Paper

The life cycle of freshwater shrimp Macrobrachium rosenbergii sp.

Shrimp is one of the world‘s most popular shellfish and is a part of almost every ethnic cuisine. The freshwater shrimp Macrobrachium rosenbergii sp. belongs to genus Macrobrchium which the largest genus of the family Palaemonidae. It locally known as udang galah is distributing from north-west India to Asia (Banu & Christianus, 2016). In Malaysia, the freshwater shrimp can be found in most inland freshwater areas including ponds, rivers and lakes. The adult freshwater shrimp requires a brackish environment in freshwater function for the larvae development (Mohd Shamsudin et al. 2013). Nowadays, consumers prefer seafood crustacean especially freshwater shrimp Macrobrachium rosenbergii

is spawning the eggs. Mating process of Macrobrachium rosenbergii sp. occurs all around the year and there are peaks sometimes which relate to environment factors. During copulation, the male will releases gelatinous semen from the sperm sack stored in its body on the ventral thoracic region between the peleopods (walking legs) of the female (Nandlal & Pickering, 2005). The ripe female after finished the pre-mating moult will contribute ideal mating (New, 2002). Meanwhile, the female starts to lay eggs and it discharges the eggs out from the gonopores into the brood chamber on pleopod during the copulation. The eggs have been attached on the female pleopod (walking legs) will be fertilized by the spermatophore (male semen) in the water. The female holds the eggs in the brood chamber and are stuck onto the ovigerous setae. Afterwards, the eggs are kept well aerated by the result of vigorous movements of the peleopods (Gupta et al., 2012). The fully mature female shrimp can produce around 80 000 to 100 000 eggs during one spawning (New, 2002). Then, “incubation of the fertilized eggs takes around 18-21 days, depending on the temperature (best result are obtained when water temperatures 28o-30oC). During this time the berried female aerates the eggs under its tail. The eggs are slightly elliptical in shape and initially yellowish to bright orange in colour then gradually change to greyish a few

According to Jason et al. (2016), the protozoea forms after the nauplius phase through several moults. The body of the shrimp starts to form during this phase. In addition, throughout this phase, the protozoea begin to develop into more shrimps-like features (Varden, Coleman & Ducote, 1999). The protozoea larvae have feathery appendages and elongated bodies. However, the protozoea body is still differing than the shape of an adult shrimp (Brun, Chimp & Moullac, 2001). Moreover, the heat and light from the sun plays major role during this phase because it is crucial for the detrimental development of the larvae (Jason et al. 2016). Apart from that, the shrimp-like feature now begins to feed on micro-algae (Varden et al. 1999). This protozoea moulting stage lasts for six days before metamorphose to mysis phase (Brun et al.,