TO STUDY THE BIOECOLOGY OF CASPIAN SHRIMPS

Only two species of shrimps live in the Caspian Sea: Palaemon elegans and P. adspersus (Crustacea, Decapoda: Palaemonidae), which were introduced to the Caspian Sea in 1931-1934 during the introduction of mullets. Data on the biology of these species of shrimps are reflected only in the works by E.N. Kudelina (1950) and M.P. Marochkina (1980). This determines the relevance of research on the current state of the Caspian shrimp population. The material was collected in various areas of the Middle Caspian Sea in the summer-autumn period. Both species live up to five meters deep. P. elegans prefer coastal underwater objects with dense thickets, P. adspersus - open shallow waters with sandy-muddy soil. To the north of Makhachkala, P. elegans predominates, to the south, the number of both species is the same, and to the east, P. adspersus dominates. The characteristics of breeding females are presented, and the dependence of fecundity on the length of egg-bearing females is revealed. The absolute fecundity increased with the increase in the size of the females. Regression equations reflecting the relationship between fecundity and length of egg-bearing females of P. elegans and P. adspersus are calculated, expressed by power equations, respectively: E = 0.044947 · L265356 and E = 2.323 · L17.4, where: E - fecundity, L-length. In October 2017, in May and October 2018, several specimens of the subtropical freshwater shrimp Macrobrachium nipponense were found downstream of the Terek River. Probably, in the near future, the species composition of the Caspian shrimp will be replenished with another species.

UJI DAYA HAMBAT MINYAK SAWIT (CPO), BAWANG PUTIH, DAN KUNYIT TERHADAP BEBERAPA JENIS BAKTERI Vibrio sp.

Pathogenic bacteria infection does not only occur in ponds but also occur in shrimp seed rearing ponds. shrimp farmers have already known the term firefly disease caused by infection of Vibrio harveyi bacterium. Prevention of the growth of Vibrio sp. in water is important to avoid acute and chronic disease in shrimp. Population control of Vibrio sp. in water can be done by using natural antibiotics derived from plants (herbs). There are many types of plants that contain antibacterial compounds or substances and have been widely used by humans. the plants that could be antibiotics are CPO, garlic and turmeric. Based on the results obtained from this study, it indicates that garlic can inhibit the growth of V. harveyi, V. parahaemolitycus, and V. alginolitycus bacteria. The use of garlic in the vanname shrimp seeds can result in the death of the shrimp. CPO and turmeric cannot be used as antibiotics against V. harveyi, V. parahaemolitycus, and V. alginolitycus bacteria.

Effect of stingray (Hemitrygon akajei) foraging on a ghost shrimp population (Nihonotrypaea harmandi) on an intertidal sandflat, western Kyushu, Japan

Callianassid shrimp residing in deep burrows have large bioturbating effects on marine soft-bottom communities. A few predators that excavate deep pits could have substantial effects on shrimp populations, as well as knock-on effects. Processes and consequences of such effects on shrimp populations are poorly understood. On a 300-m-wide intertidal sandflat area between tide marks in western Kyushu between 1989 and 1994, shrimp population densities were stable, reaching >1300individualsm–2. Dasyatid stingray feeding pits reaching depths up to 20cm occurred abruptly in large numbers in 1994, after which shrimp densities decreased yearly to hundreds of individuals per square metre in 2001. The densities of ray feeding pits formed per day were monitored every or every other spring tide between 2000 and 2001. Schools of rays were enclosed during submerged times and their body sizes recorded alive to determine size-frequency distribution. The body-size frequency distributions of shrimp were compared among the gut contents of several rays, ray feeding pits and intact sandflat. Reductions in the shrimp density per ray feeding bout compared with the density on the intact sandflat were recorded. A model of daily predation at different seasonal rates was used to simulate the yearly change in shrimp density. The result was consistent with the actual change.

Glimpses On White Spot Disease in Shrimps and its Significance in e-Resource Development

The worldwide distribution of White Spot Disease (WSD) instigated by White Spot Syndrome Virus (WSSV) is one of the most pathogenic and devastating viruses in shrimps and crustaceans. WSSV categorized into a new family named Nimaviridae causes the disease that has been considered as havoc as it severely affects the shrimp population and in its most fatal form due to its high virulence, it has the ability to wipe out all the shrimp population within a week. Surprisingly till date, no effective drugs are available to prevent the disease because of incomplete understanding on the disbandment of the disease mechanism and further protein of this virus has not shown any homology with already existing viral proteins. Earlier, many attempts were made to understand the mechanism of entry, propagation and spread of this virus within the host, but till now, the information and knowledge generated from these studies have not been compiled with an aim to construct systematic and comprehensive e-resource covering information relating to genes, proteins and protein interactions of the disease. To accomplish this, it is imperative to have the understanding about the available resources that contains information and knowledge about this disease so as to provide the complete understanding about the disease and the related phenomena. Such publically available resources can be of extreme importance in developing an e-resource in the form of an online database that might be of much useful to the shrimp and allied researchers and in future of tremendous benefit as the shrimp researchers might perform many operations from the 'omics' data stored in the database. The present paper discusses about WSD, its resources and utility in accomplishing database in a nutshell.

Acoustic-based model estimation of snapping shrimp populations and the effects of a sponge die-off

ABSTRACTHuman use of the ocean and its ecosystems continues to degrade coastal habitats around the world. Assessing anthropogenic impacts on these environments can be cost and manpower intensive; thus, developing rapid, remote techniques to assess habitat quality has become increasingly important. We employed autonomous hydrophone receivers to record the soundscapes of healthy hard-bottom habitat in Florida Bay, Florida (USA) and hard-bottom areas impacted by sponge die-offs. We also recorded sounds emanating from individual sponges of three species that were isolated in underwater sound booths, and then enumerated the invertebrates (mostly snapping shrimp) dwelling within the canals of each sponge. From these recordings, a modified cylindrical sound propagation model was used to estimate distances to snapping shrimp snaps. Using the program Distance, which applies distance sampling theory to cue count surveys, we estimated snapping shrimp population density and abundance within both habitat types. More snapping shrimp snaps per unit time were recorded in healthy hard-bottom areas as compared to degraded hard-bottom areas. In addition, the average distance to a snap source was greater within degraded hard-bottom areas than within healthy hard-bottom areas. As a consequence, the estimated density and abundance of snapping shrimp were one to two orders of magnitude greater within healthy habitat than within degraded habitat. This study demonstrates the feasibility of using acoustic sampling and modeling to rapidly assess populations of soniferous benthic indicator species, whose vocalizations may yield indirect estimates of habitat quality.