Diseases of environmental\norigin are without doubt the most commonly encountered by aquatic professionals\nand hobbyists alike. Pathogenic disease often arises as a consequence; other\ncauses of disease can be much more esoteric and less regularly encountered. An\nawareness is still vital to anyone with an interest in fish health and welfare.\n<\/p>\n\n\n\n
Many diseases can have their\nroot in malnutrition, fish can be fed incorrect levels of proteins, fats or\ncarbohydrates, but more commonly it is an imbalance of micronutrients such as\nvitamins and minerals that lie at the heart of the problem. The most commonly\ncited example is a deficiency of ascorbic acid – vitamin C, this antioxidant\nagent is vital for many biological functions not least collagen manufacture and\nmany elements of immune system function. Fish show repeatable symptoms of\ndeficiency if not enough is provided in the diet. Ensuring enough of this\nvitamin reaches the fish is complicated by the water soluble nature of the\nvitamin and its inherent instability in dry fish foods. Food manufacturers therefore\nadd stabilised forms of vitamin at elevated levels to ensure the required\namount reaches the fish. Avoiding food past it\u2019s sell by date is a reliable way\nto avoid vitamin C deficiency in fish.<\/p>\n\n\n\n
Disease can also have its root\nat the genetic level; genes are sequences of the genetic material that code for\nspecific proteins, these then form the builders and building blocks of the\nfish. Just as typographical errors can be made in a sentence, errors in the\nsequence of base chemicals in the genetic code lead to mistakes in the protein\nproduced. These mutations are often harmless causing no visible or\nphysiological effect in the fish; occasionally the error has a consequence. This\ncan lead to disease in should this alteration of essential protein structure\nmean it is no longer be able to perform its role in the complex body system of\nthe fish. We should also remember though that it is this mutation that gives us\nthe infinite variety of life.<\/p>\n\n\n\n As more research into fish\nbehaviour and welfare is conducted, it is becoming more apparent that the\npsychological well being of the fish is just as crucial as good water quality,\ndiet, genetics and the absence of pathogens. Aquarists have known for years\nthat behaviour is a key player in fish health, fish stressed by aggressive\nattention from a socially dominant tankmate or breeding partner soon succumb to\ninfectious disease. Even too much attention from humans (banging on the\nglass!), can weaken timid fish. However psychological well being extends much\nfurther than the fish not being bullied or scared. \u2018Environmental enrichment\u2019\nis a hot topic among many animal husbandry professionals; this can be defined\nas the provision of environmental stimuli to encourage physical and mental\nactivity. Examples of environmental enrichment in the ornamental fish world\ninclude target training Archer fish (Toxotes\njaculatrix<\/em>) or puzzle solving for a food reward in Common Octopus (Octopus vulgaris<\/em>), more recently a\ngoldfish training kit has become available to buy on the internet! <\/p>\n\n\n\n At a much more simple level\nthe provision of d\u00e9cor to offer cover, gravel or sand for benthic species, flow\nfor riverine species or the correct spawning substrate would also be considered\nenvironmental enrichment, because these make the habitat more conducive to allowing\nthe fish complete its natural behavioural repertoire. It is only through\ncutting edge welfare research involving monitoring stress markers such as catecholamine\nand corticosteroid hormones and endogenous opiods (natural pain relief\nchemicals), that the importance of the fish\u2019s psychological well being will\nbecome apparent.<\/p>\n\n\n\n So let\u2019s return to our\noriginal definition of \u2018health\u2019 as an absence of disease. Disease symptoms are\ncaused when the fish\u2019s environmental requirements are not met, when pathogens\ninfect, when the diet is incorrect, from a genetic origin or when the fish\u2019s\npsychological needs are not met. Thus when appraising the health of our\nfish we must consider all of these factors.<\/p>\n","protected":false},"excerpt":{"rendered":" Defining the concept of \u2018health\u2019 can be very tricky, generally, animals are considered \u2018healthy\u2019 if they are free from disease, however, disease is itself defined as a state of ill health! These circular definitions can lead to confusion so perhaps a closer look at the causes of ill health in fish may help to hone […]\n","protected":false},"author":2,"featured_media":2489,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[221,163],"tags":[],"class_list":["post-2488","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-disease","category-fish"],"yoast_head":"\n![\"\"](\"https:\/\/blog.tetra.net\/en-en\/wp-content\/uploads\/2020\/08\/tetra_mid.jpg\")
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