MYXOSPORIDIAN PARASITES OF FRESH WATER FISH (Catla catla) IN CULTURE PONDS, KRISHNA DISTRICT, A.P

The myxosporean species are typically defined by the size and shape of the spores released by vertebrate hosts. These are previously thought to be multicellular protozoans are to be considered animals by many scientists. Recent molecular studies suggest that they are related to Bilataria with being closer, but with Bilataria being somewhat closer in some genetic studies. The examination of fresh water fishes captured in the culture system water bodies of Krishna district, Andhra Pradesh, India revealed the presences of two Myxosporidian Myxobolus sps, Ceratomyxa sps. In catla catla which were collected from Feb-2014 to Feb-2015. The infested fishes showed some macroscopic creamy whitish nodules round or oval shape and its number varied from 2 to 4 cysts. These nodules contents milky fluid filled with mature spores present study results the occurrence of the three myxosporidians and the health risks to their hosts and revealed the myxosporidians encountered from various organs of the host fish. Skeletal deformation in matured major fish by myxobolus infection cause damage to its hosts through attachment of Triactinomyxon spores and migrations of various stages through tissues along nervous as well as by digesting cartilage. Other symptoms include skeletal deformaties and ‘whirling behaviour’ in young fish which thought to have been caused by a loss of equilibrium caused by damage to the spinal cord and lower brain stem. © 2016 Universal Research Publications. All rights reserved KeywordsMyxosporidian, Myxobolus sps, Ceratomyxa sps, Catla catla, Parasitic disease. INTRODUCTION Members of the Myxozoa are microscopic metazoan parasites with an extremely reduced body. The dimensions of the myxospore, the typical myxozoan stage in fish hosts, range usually between one hundredth and two hundredth of a millimetre. Myxospores consist of several cells, which are transformed to shell valves, nematocyst-like polar capsules with coiled extrudible polar filaments and amoeboid infective germs. Myxospores develop in plasmodia (trophozoites), which can be very large and polysporic (generally histozoic in host tissue) or small and monoor disporic (coelozoic in organ cavities). Myxozoans are parasites of fish, worms (oligochaetes and polychaetes) and bryozoans. Few representatives were found as parasites of amphibians and reptiles, and recent findings confirmed the ability of myxozoans to infect mammals (Prunescu et al., 2007, Dyková et al., 2007) and birds (Bartholomew et al., 2011). Humans as potential hosts for myxosporea were also reported (Boreham et al., 1998, Moncada et al., 2001), however, myxospores were detected in faecal samples and probably just passed through the digestive tract. Myxozoa Grassé, 1970 contains two classes: Malacosporea Canning, Curry, Feist, Longshaw Okamura et al., 2000 and Myxosporea Bütschli, 1881. Malacosporea includes only two genera (Tetracapsuloides and Buddenbrockia) with a total of three described species. Myxosporea includes about 2200 species in 60 genera. Wolf and Markiw (1984) discovered myxosporean life cycles altering between two host species – fish and annelid worm. The myxospore is ingested by annelids and then the myxosporean undergoes a schizogony and a gametogony. Finally, the parasite develops into an actinospore, a triradiate myxosporean spore, which infects the vertebrate host. Here, the sporoplasm released from the actinospore divides by endogony, and then presporogenic multiplication of the myxosporean occurs. The life cycle is completed with the development of mature myxospores in sporogonic plasmodia. The annelids are definitive hosts whereas vertebrates are intermediate hosts for Myxosporea. The rediscovery of Buddenbrockia plumatellae, a wormlike animal, as a myxozoan species was an important clue to the origin of Myxozoa (Monteiro et al., 2002). SSU rDNA of this enigmatic worm showed its close relationship to Tetracapsuloides bryosalmonae, and B. plumatellae was assigned to Malacosporea, the sister group to Myxosporea. Consequently Myxozoa were considered to be bilaterians. or their close relatives (Monteiro et al., 2002). However, phylogenetic analysis based on sequences of numerous Available online at http://www.urpjournals.com International Journal of Research in Biological Sciences Universal Research Publications. All rights reserved