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This study investigated short-term effects of high temperature on survival and feed consumption of the tropical banana shrimp Penaeus merguiensis. Three 7-day experiments were conducted with three age group of P. merguiensis: PL25 (postlarvae 25 days old), PL50 and PL100. In these experiments water temperature was maintained at 27 °C in the control, but increased to 32, 35, 38 and 41 °C at a constant rate of 1 °C every 8 h. Once reached, the desired level of water temperature was kept stable until the end of the experiment. Results showed that water temperature above 35 °C significantly reduced survival of the experimental shrimp (P

Hepatopancreatic parvovirus infection is associated with reduced growth rates of prawns during the juvenile stages and overt mortalities. Hepatopancreatic parvovirus was purified from Penaeus merguiensis from northern Queensland and a partial consensus sequence of 5.9 kb was obtained. Nucleotide comparisons revealed that the Australian isolate of HPV has a nucleotide similarity (87%) closer to HPVchin and the full sequence of HPV Penaeus monodon (PmDNV) (6321 bp) than to HPVsemi (83%). Three putative open reading frames were identified. The first open reading frame encoded a nonstructural protein (NS2) and shared an amino acid similarity of 86% with PmDNV. The second ORF overlapped the first open reading frame and shared 93% and 26% amino acid similarity with PmDNV and PstDNV, respectively, and encoded NS1. The third ORF encoded the viral structural protein and shared an amino acid similarity of 73% with the capsid protein of PmDNV and HPVchin. The phylogeny suggests that the Australian HPV isolate is closely related to the Korean HPVchin isolate than to the Indian HPVsemi and Thai PmDNV isolates. HPV strains may be following the phylogenetic relationship of penaeid prawn hosts rather than their geography.

The maturation rate and spawning performance of ablated Penaeus merguiensis were significantly (P 0.05).

The rates of closure of wounds made by streamer tags in penaeid prawns were measured, and the effect of streamer tag placement and prawn size on survival rate was assessed. Penaeus esculentus (27–39 mm carapace length (CL)) were tagged horizontally through the middle of the second abdominal segment. After tagging, the cuticle of the prawns grew inwards, during the intermoult period, forming a tube that joined between 48 (two moults) and 90 days (four moults) after tagging. Two hundred and thirty P. esculentus, recaptured after being tagged in three different positions with streamer tags and released at sea, were also examined. Tube formation was fastest in prawns tagged through the middle of the first segment (P

Studies conducted on prawn, Penaeus merguiensis (de Man, 1888), from Goa and Devgarh (Maharashtra) waters showed higher average values of tail weight and other morphometric characters in Devgarh. The coefficient of variation in females is almost twice that in males in both localities. Stepwise sequential regression analysis indicated that morphometric characters like partial carapace length (PCL), exopod of uropod length (EUL) and posterior abdominal circumference (PAC), either individually or in combination, give a more accurate estimate of tail weight than the other 14 possible variables, and can be used for selection of the broodstock in aquaculture.

When juvenile Penaeus merguiensis were fed four times daily they increased in weight more rapidly and utilized their food more efficiently than when fed once per day. The maximum ration for prawns given a commercial dry pellet was approximately 12.0% of the wet body weight per day and changed very little as the prawns grew from 0.5 to 1.3 g in indoor culture. Food conversion efficiency declined with increasing weight and ration size but the relative loss in efficiency was least when rations were maintained near to the maximum. Evidence is presented for the existence of a negative K-line relationship in P. merguiensis.

In growth trials with juvenile Penaeus merguiensis the incorporation of a complex vitamin supplement into diets based on freeze-dried Mytilus edulis , at 3.5% by weight, increased growth rate but no additional advantage was gained at higher levels of inclusion. When a mineral supplement was incorporated at 7.0% by weight in addition to the vitamins, a further improvement in growth response was achieved. Doubling the levels of both supplements, however, did not influence this result significantly. The inclusion of minerals alone in the diet, at either 7.0% or 14.0% by weight not only failed to increase growth but resulted in severe mortalities.

The requirement of juvenile Penaeus merguiensis for dietary protein and energy was assessed in growth trials performed in indoor recirculation systems using rations based on freeze-dried Mytilus edulis meal. From the results of these experiments evidence was obtained to indicate that the rate of food consumption in this prawn is related to the energy content of the diet. The implications of this are that the protein level required to support maximum growth and optimum protein conversion efficiency are also energy dependent. Optimum protein levels were estimated in the range 34.0–42.0% for diets of energy content 2.9–4.4 kcal/g. A possible scheme relating food consumption, energy production and growth in P. merguiensis is presented.

Penaeus merguiensis was cultured through three generations in laboratory recirculation systems. Populations of 24–76 prawns produced, on average, 2–15 batches of 44 000 eggs per month throughout a 16-month period. Survival to metamorphosis was over 50% and post-larvae reached a size (0.15 g live weight) suitable for stocking in “grow-out” tanks 50–60 days after being spawned. In the subsequent 16 weeks prawns reached 5–7 g live weight with 24–58% survival.

Approximately 50,000 post larvae of Penaeus merguiensis were produced in a 0.2-ha. pond which was stocked with adults and fertilized only with organic manures.

1 000 post larval Penaeus merguiensis were grown in Fiji to commercial size within 90 days in a 0.5-acre pond stocked with milkfish and rabbit-fish. Growth curves for males and females are presented.