Shrimp Penaeus Merguiensis Research Articles

Effects of high temperature on survival and feed consumption of banana shrimp Penaeus merguiensis

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 < 0.01). Shrimp survival was only 24% and 0% in the 38 °C and 41 °C treatments, respectively while ranging between 91 and 96% in the other treatments. Feed consumption was significantly affected by both ambient water temperature and shrimp size (P < 0.01). It was highest in the 41 °C treatment (1.7%/shrimp×day), followed by the 38 °C treatment (1.3%/shrimp×day) (P < 0.01). Feed consumption in the PL50 and PL100 age groups was 3.5 to 4.0 fold higher than that in the smallest age group PL25 (P < 0.01). This study suggests that P. merguiensis in tropical areas may survive water temperature up to 35 °C in commercial shrimp ponds.

Length-weight relationship and condition factor of white shrimp Penaeus merguiensis captured in ecosystem mangrove of Bagan Asahan, Tanjungbalai, Asahan, North Sumatra, Indonesia

White Shrimp Penaeus merguiensis was commonly found in Mangrove Ecosystem of Bagan Asahan Village. The purpose of this research are to determine length-weight relationship and condition factor of white shrimp Penaeus merguiensis around ecosystem mangrove waters in Bagan Asahan Village. This research was conducted for 3 month in Maret until Mei 2017 with determination of research station used purposive sampling method. The shrimp samples were taken by shrimp trawl. The result showed that 98 shrimp which consists of 58 males and 40 female. The carapace length of female shrimp between 6,05 – 22,125 mm and total weight ranged from 0,12 – 6,95 g. Male shrimp had carapace length between 7.125 – 18.25 mm and total weigth ranged from 0.14 – 3.82 g. Female and male white shrimp had different growth pattern. Female shrimp had b = 2.984 included in negaive allometric and male shrimps with b = 3.187 included in positive allometric. The value of correlation coefficients was more than 90% for both male and female showed very strong relation between length carapace and body weight. The value of shrimp condition factor ranged from 0.570 – 1.773 and included to flat (thin) body shrimp.

Emilia sonchifolia extract activity against white spot syndrome virus and yellow head virus in shrimp cell cultures.

Emilia sonchifolia (L.) DC is a plant used in traditional medicine to treat several viral and bacterial diseases. The antiviral activities of selected Sephadex LH-20 column fractions and HPLC subfractions of an acetone extract of E. sonchifolia leaves were determined in shrimp Penaeus merguiensis primary lymphoid cells infected with either white spot syndrome virus (WSSV) or yellow head virus (YHV). WSSV and YHV replication was quantified using quantitative real-time PCR tests targeted to the VP19 and ORF1b gene transcripts, respectively. In lymphoid organ cells exposed to 100 µg ml⁻¹ of either the Sephadex fraction F14 or the HPLC F14 subfraction SF4, both fractions caused reduced replication, but YHV replication was reduced only by SF4. In the asthiazolyl blue mitochondrial enzyme activity assays to assess extract cytotoxicity, >60% of primary lymphoid organ cells remained viable following exposure to 100 µg ml⁻¹ of either F14 or SF4. GC-MS analysis of the HPLC F14 subfraction SF4 showed that it contained 2,4-di-tert-butylphenol. This study is the first to show that E. sonchifolia leaf extracts might be useful as bioactive agents to protect shrimp against viruses such as WSSV and YHV.

Mercury accumulation in selected tissues of shrimp Penaeus merguiensis from Musa estuary, Persian Gulf: variations related to sex, size, and season.

The levels of mercury in tissues of Penaeus merguiensis from Musa estuary, northwest of the Persian Gulf, were investigated. This study assessed the relationship between mercury levels in hepatopancrea, gill, and muscle with sex, size, and season. The order of mercury concentrations in tissues of the shrimp P. merguiensis was as follows: hepatopancreas > gill > muscle. There was a positive correlation between mercury concentrations in shrimp species with sex and size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. Also, there was a positive correlation between mercury concentrations in shrimp species with its food source. Therefore, female species feed more on shrimp and plant and are contaminated with high levels of mercury. There was significant difference (p < 0.05) in mercury levels between different seasons; higher mercury levels were found in July (summer season).

Isolation and characterization of bacteria from the copepod Pseudocaligus fugu ectoparasitic on the panther puffer Takifugu pardalis with the emphasis on TTX

A total of 50 bacterial isolates was obtained from the copepod Pseudocaligus fugu, which is a common parasite, collected from the body surface of the panther puffer Takifugu pardalis. On the basis of colony characteristics, these bacterial isolates were grouped into six types, of which only two (Types-I and -II) showed a high affinity for adhesion to the carapace of the banana shrimp Penaeus merguiensis. These two types of adhesive bacteria were identified through 16S rRNA sequence analysis as Shewanella woodyi (Type-I) and Roseobacter sp. (Type-II). Representative isolates of these two adhesive bacteria were examined for tetrodotoxin (TTX) production by high-performance liquid chromatography (HPLC)–fluorometric system, gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS). It was rather unexpectedly revealed that TTX and anhydroTTX were present in the supernatant of culture of the Type-II isolate Roseobacter sp.

Effects of secondary crops on bacterial growth and nitrogen removal in shrimp farm effluent treatment systems

Secondary crops provide a means of assimilating some effluent nitrogen from eutrophic shrimp farm settlement ponds. However, a more important role may be their stimulation of beneficial bacterial nitrogen removal processes. In this study, bacterial biomass, growth and nitrogen removal capacity were quantified in shrimp farm effluent treatment systems containing vertical artificial substrates and either the banana shrimp Penaeus merguiensis (de Man) or the grey mullet, Mugil cephalus L. Banana shrimp were found to actively graze biofilm on the artificial substrates and significantly reduced bacterial biomass relative to a control (24.5±5.6mgCm−2 and 39.2±8.7mgCm−2, respectively). Bacterial volumetric growth rates, however, were significantly increased in the presence of the shrimp relative to the control (45.2±11.3mgCm−2 per day and 22.0±4.3mgCm−2 per day, respectively). Specific growth rate, or growth rate per cell, of bacteria was therefore appreciably stimulated by the banana shrimp. Nitrate assimilation was found to be significantly higher on grazed substrate biofilm relative to the control (223±54mgNm−2 per day and 126±36mg Nm−2 per day, respectively), suggesting that increased bacterial growth rate does relate to enhanced nitrogen uptake. Regulated banana shrimp feeding activity therefore can increase the rate of new bacterial biomass production and also the capacity for bacterial effluent nitrogen assimilation. Mullet had a negligible influence on the biofilm associated with the artificial substrate but reduced sediment bacterial biomass (224±92mgCm−2) relative to undisturbed sediment (650±254mgCm−2). Net, or volumetric bacterial growth in the sediment was similar in treatments with and without mullet, suggesting that the growth rate per cell of bacteria in grazed sediments was enhanced. Similar rates of dissolved nitrogen mineralisation were found in sediments with and without mullet but nitrification was reduced. Presence of mullet increased water column suspended solids concentrations, water column bacterial growth and dissolved nutrient uptake. This study has shown that secondary crops, particularly banana shrimp, can play a stimulatory role in the bacterial processing of effluent nitrogen in eutrophic shrimp effluent treatment systems.

THE EVIDENCE OF BACILLIFORM VIRUS A CAUSATIVE AGENT OF WHITE SPOT SYNDROME OF WHITE SHRIMP Penaeus merguiensis

The rod-shape virus particles were found in the hyperthrophied nucleus and cytoplasm of diseased white shrimp Penaeus merguiensis naturally infected by White spot syndrome (WSBV). In natural infection cumulative mortality of shrimp were very high, 95 percent of population were dead in 3-7 days, and 5 percent of shrimp population survived. The disease was outbreak in intensive culture farms used the closed circulation sea water system. Others crustacean such as crabs and bentatos were not infected by WSBV at time of sampling. The virus particle were rod-shape ranging from 78 10 nm in diameter and 280 10 nm in length. The pathogenic bacteria mainly dominated by genus Vibrio sp were isolated from shrimp.

White spot syndrome virus (WSSV) infects specific hemocytes of the shrimp Penaeus merguiensis.

White spot syndrome virus (WSSV) was specifically detected by PCR in Penaeus merguiensis hemocytes, hemolymph and plasma. This suggested a close association between the shrimp hemolymph and the virus. Three types of hemocyte from shrimp were isolated using flow cytometry. Dynamic changes of the hemocyte subpopulations in P. merguiensis at different times after infection were observed, indicating that the WSSV infection selectively affected specific subpopulations. Immunofluorescence assay (IFA) and a Wright-Giemsa double staining study of hemocyte types further confirmed the cellular localization of the virus in the infected hemocytes. Electron microscopy revealed virus particles in both vacuoles and the nucleus of the semigranular cells (SGC), as well as in the vacuoles of the granular cells (GC). However, no virus could be detected in the hyaline cells (HC). Our results suggest that the virus infects 2 types of shrimp hemocytes--GCs and SGCs. The SGC type contains higher virus loads and exhibits faster infection rates, and is apparently more susceptible to WSSV infection.

Fish predation on mangrove-associated penaeids: The role of structures and substrate

The effect of habitat structure and substratum on predation of the greasyback shrimp Metapenaeus ensis (De Haan), white shrimp Penaeus merguiensis De Man and tiger shrimp Penaeus monodon Fabricius by sea bass Lates calcarifer Bloch and mangrove snapper Lutjanus argentimaculatus (Forsskal) was evaluated. The shrimp juveniles measured 6–15 mm in carapace length; fish measured 6.5–12.5 cm in standard length; structure types were pneumatophores of the mangrove Sonneratia griffithii Kurz and dried coconut leaf bracts; structure densities were 0, 32 and 98 pneumatophores per tank; and sediment particle sizes were pebbles, sand-granules and silt–sand.Predation on shrimp was significantly higher in controls or bare sand (48.7%) than among pneumatophores (29.9%), but not among leaf bracts (43.5%). Shrimp mortality was also significantly higher on bare sand (72.9%) compared to medium-density (54.2%), but not high-density (68.8%), pneumatophores. Fish predation on the burying shrimp M. ensis was affected by predator type but not by sediment size. The generally higher predation rates of snapper may be due to their habit of leaving unconsumed pieces of shrimp, whereas sea bass which devour whole prey require fewer shrimp to reach satiation. Moreover, the presence of structures did not affect sea bass behaviour of chasing prey among pneumatophores and under leaf bracts, but reduced predation by the relatively passive snapper. Predation rates among pneumatophores vs. control, and among medium-density pneumatophores vs. bare sand, were lower for P. monodon but not P. merguiensis. This may be related to the greater and more frequent use of (laboratory) shelters by juvenile tiger shrimp compared to white shrimp. The results demonstrate that the effective provision of shelter depends not only on structure type and density but on the behaviour of predator and prey as well. The use of mangrove structures (pneumatophores) by juvenile shrimp as refuge from predation is also documented for the first time.

The Toxicity of Five Native Thai Plants to Aquatic Organisms

Five species or native Thai plants were bioassayed as toxicants against the cladoceran Moina sp., the fishes Oreochromis niloticus and Anabas testudineus, the shrimp Penaeus merguiensis, and the snail Cerithidea cingulata. The 24-h LC50 of each plant to each test species was determined. Diospyros diepenhorstii is the least effective plant extract against all five test organisms, while Maesa ramentacea and Sapindus emarginatus are the most effective plant extracts against Moina sp., 0. niloticus and A. testudineus. The lethal concentrations of all plant extracts to test fish are greater than that to shrimp. Moreover, all plant extracts are more effective against 0. niloticus than A. testudineus. Pittosporum ferrugineum and S. emarginatus have potential against snail pests. Among the five plants, M. ramentacea showed the highest toxicity to 0. niloticus. Toxicity to 0. niloticus or M. ramentacea (15-30 mg,J-1) was about half that of tea seed cake (6-15 mg,J·1). However, improvement of M. ramentacea toxicity is feasible. These results are useful for developing botanical pesticides for selective killing of undesired aquatic organisms.