Fish and Water Temperature

Understand how the drop in its results interfere with thermometers reeled in.

Temperature decreases are always synonymous with reduction in the biological activity of living beings, no matter if the region inhabited is tropical, subtropical or temperate, with these last two are far more intense effects. Plants, for example, reduce your growth, being common to many species lost branches and leaves. In the case of animals, we can use as an example the own human being, which during the cold he stays longer inside (preferably under a blanket!). Substantial falls in thermometers are deepest in the South and East of our country. At this time the “cold waves” reach fishermen and fish with greater frequency.

Unlike birds and mammals that maintain the ideal body temperature constant (and different from the environment), the internal temperature of fish, amphibians and reptiles is always equal to that of the middle that surrounds-in the case of fish, water. It’s called exothermic process, known in ancient times as ectotermia. Who bought aquarium fish knows, or should know, that release them without first adapting them to the aquarium water for at least half an hour can be fatal. And this is precisely the exothermic process.
-The thermal shock is triggered when different temperatures between the body of the fish and the aquarium water lead to a collapse of the metabolic activities in the body of the animal, committing various organs and systems, and may lead to death.
-The decrease of temperatures during the cooler months, average temperatures of the waters also decrease, causing a reduction in the level of activity of fish. The fluxes animals generally have an optimum temperature range for operation of its bodies, called “thermal comfort”.
-Temperature receptors in the body surface of the fish, usually detect temperature differences on the order of 0.1° C and can reach up to 0.03%. These bodies are composed of free nerve endings, finely branched, distributed through the epidermis. The presence of these receptors help the fish find layers of warmer water, or perform offsets in search of warm waters in the case of tropical species.
-When the water temperatures drop and leaving the comfort range, these organisms present decrease in their body activities. For much of the Brazilian fish, the ideal temperature range is between 24 and 28° c.

Cold: Flee or Face
-What to do when you want to fish in the coldest season of the year? Although most species present reduction of their activities, some can be caught, but in smaller quantities.
-Are examples of fish that live in the River Plate Basin (rivers Paraná, Paraguay and tributaries), who possess any adaptation in the months of winter and the colder water, unlike most of the species of the Amazon. Fish like Peacock bass, corvinas and freshwater rays are extremely sensitive to temperature drops. Some species, especially the navies, present degree thanks to the migration phenomenon.
-Look for warmer places like the northeastern region, can be a good option for those who fish in the sea. Coincidentally, when it cools down in the South and Southeast, starts the season of so-called “Amazonian summer”, when the level of the rivers begin to download with the drought, which is ideal for fishing. So, if you are in the South or Southeast, use this information to plan that special fishing trip away from home. But for those who can’t afford or don’t want to travel more than a few hundred kilometers, what is the solution? The alternative is to try to capture the so-called “winter fish”.
-These species are adapted to live in waters with lower temperatures, allowing your fishing even during unfavorable periods to most tropical fish.
-While much retracts because of the cold, the fish more tolerant still in full swing. The fisherman can then return your attention to these species.
-In fresh water, we can highlight stop South and Southeast regions fishing for carp, black bass, catfish, jundiá (rhomdia spp), cenarás, and trout lambaris.
-In salt water, anchovies, betaras, bass, mullets and sororocas. Although present throughout the year, these fish are still in full swing. Migrate along the coast, are most active and numerous shoals form (case of mullet, sororoca and anchovies).
-In dams or sheltered marine areas such as bays and coves, the fisherman can get layers of warmer water in search of ambient temperatures pleasant to fish. Large bodies of water feature laminate, with layers that have different temperature and dissolved oxygen levels, implying a differentiated distribution of species by water. When entering a cold front, the surface water cools and becomes denser. According to the intensity and the duration of the cold, this layer moves toward the bottom, by modifying the position of the lower water layers. In such situations, the use of probes to locate fish is an excellent choice. It’s good to remember that cold front entries in the Pantanal and Amazon regions often cause large fish kills. Although the temperature is the main reason in some homes, most often the main cause is the lack of oxygen (often with zero rate, are displaced to the surface, killing fish by asphyxiation. That explains the large amount of fish breathing on the surface, observed on these occasions. Is the famous natural process of “dequada”, very common in the Pantanal (intensified by the decomposition of organic matter cycles ebb and full). In the Amazon, the arrival of cold fronts, especially in rivers from the right margin (as Xingu and wood), are known locally as “chills”, and can lead to substantial drops in atmospheric temperature at 15° C.
Like every good fisherman, use your creativity to adapt to conditions imposed by the cold, whether intermittent or lasting. And remember, despite the water temperature being the key factor in most situations, you should always be aware of variables such as phase of the Moon, tides, and atmospheric pressure. Study the biology of the species chosen and the techniques to catch them, plan well the fishery and … hooks in the water!