Ingestion of Brachionus plicatilis and Artemia salina nauplii by mud crab Scylla serrata larvae

Abstract

Two feeding experiments were conducted to determine if Brachionus plicatilis and Artemia salina nauplii were ingested by mud crab Scylla serrata larvae. In the first experiment, larvae were fed with increasing densities of Artemia nauplii with or without Brachionus to determine consumption with increasing densities of Artemia and with increasing zoeal stage. This experiment also aimed to determine if the presence of Brachionus as an alternative prey influenced the intake of Artemia by the crab larvae. There was generally an increase in intake with increasing densities of Artemia and increased consumption of Artemia as the larvae grew. Consumption of Brachionus was consistently high in all zoeal stages. There was a significant reduction in the intake of Brachionus with increasing consumption of Artemia in the early zoeal stages (Z1, Z2, Z3), but at later stages (Z4, Z5) the intake of Artemia was no longer affected by the presence of Brachionus. In the second experiment, daily ingestion within instar of zoeal stages and megalopa were compared. There was an increased consumption of Artemia nauplii on the day before molting and increased ingestion of Brachionus on the day after larvae had molted, except at Z3. Megalopae exhibited a decline in Artemia nauplii intake on the days before metamorphosis to crablet.

Extension of Rotifer (Brachionus Plicatilis) Inclusions in the Larval Diets of Mud Crab, Scylla Paramamosain (Estampodor, 1949): Effects on Survival, Growth, Metamorphosis and Development Time

“…In the present study, rotifers and Artemia could be considered as first food for early crab larvae, when larvae in all feeding regimes could successfully metamorphosed to next stage, whereas, 100% of unfed larvae could not moult and died by day 7 (Holme, Zeng & Southgate, 2006), Similar to our study, rotifers due to their small size, low moving speed, rapid reproduction and an ability to store and contain desired nutrients (Dhert, 1996) are used as first food for early larval stages of mud crabs Davis, 2003;Baylon, Bravo & Maningo, 2004;Nghia, 2004;Ruscoe et al, 2004b;Baylon, 2009;Hassan et al, 2011), swimming crabs (Portunus spp.) Redzuari et al, 2012;Dan, Ashidate & Hamasaki, 2016a) and giant freshwater prawn (Macrobrachium rosenbergii) (Barros & Valenti, 2003).…”

“…The early zoeal stages can easily catch and ingest rotifers (Nghia, 2004) at a rate four times higher than that for Artemia, followed by the gradual reduction in the quantity of ingested rotifers to almost the quantity of ingested Artemia when the larvae reach the Z5 stage (Baylon et al, 2004). These authors also stated that the larvae at Z1, Z2 and Z3 stages had lower Artemia ingestion rates in the presence of rotifers in a combination with Artemia.…”

“…However, there was no significant difference in survival and metamorphosis of mud crab larvae among the feeding regimes where rotifers were extended from Z2 to Z5 stages. Baylon et al (2004) observed that the crab larvae increased ingestion of Artemia on the day before moulting, whereas ingestion of rotifers was increased one day after the moulting. As before the moulting, the larvae with a hard exoskeleton had higher nutrient requirements as they had to anabolise their tissues and should be strong active enough to catch and handle Artemia nauplii.…”

“…On the other hand, immediately after the moulting, the larvae were weaker with a softer exoskeleton, thereby showing a limited ability to catch Artemia. Therefore, the larvae switched their dietary preference towards rotifers to accumulate more nutrient necessary that cannot get from Artemia nauplii (Baylon et al, 2004) for maintaining and recovering energy essential for the survival and development to the next stage. The fact that increased survival of the crab larvae as increasing extended feeding of rotifers could be due to continuous accumulation of nutrients derived from both rotifers and Artemia nauplii during the larval development period.…”

Non-indigenous giant mud crab, Scylla serrata (Forskål, 1775) (Crustacea: Brachyura: Portunidae) in Malaysian coastal waters: a call for caution

“…Scylla serrata is the largest and most widespread species of genus Scylla (Keenan et al 1998;Alberts-Hubatsch et al 2015). Scylla serrata has been reported in most tropical and subtropical coastal regions of Indo-West-Pacific such as Bangladesh (Begum et al 2009), India (Ali et al 2011), Sri Lanka (Tharmine et al 2014;Amarasekara et al 2016), Indonesia (Roza and Hatai 1999;Nordhaus et al 2009), Philippines (Baylon et al 2004;Quinitio et al 2007), Australia (Keenan et al 1998) and around the oceanic islands of Indo-Pacific (Alberts-Hubatsch et al 2015), except around South China Sea (Albert-Hubatsch et al 2015;Fazhan et al 2017). Prior to the revision of genus Scylla by Keenan et al (1998), the species identification of mud crabs within the genus Scylla has been controversial and only one species, S. serrata, was being recognized (Stephenson and Campbell 1960).…”