FreshWater Aquariums

THERE ARE MANY MORE options to open a freshwater fish-keeper than to the marine aquarist.The freshwater keeper can recreate the conditions of a tropical river or lake,a background pound a hard-water Rift Valley lake, or a cold water stream.Whichever aquatic habitat you choose to create, water quality will be of great importance.Simulating the chemistry of location can be achieved using resins,minerals and sometimes peat in the mechanical filter system.These will soften, harden ,make alkaline , or acidify the water.Dilution by adding rainwater is one way to reduce hardness, while soft water can be hardened by adding limestone.The use of power filter will create the environment around the aquarium - a conditioned welcome by species accustomed to flowing waters.It is most important that there is high level of dissolved oxygen in aquarium water.This is best achieved by water aeration,regular water changes and general cleanliness.

Pea Gravel

SPECIAL NEEDS

Creating freshwater fish retreats for the fish using plants or rocks is extremely important, particularly for the more timid species.Some fishes will appreciate being shaded from overhead lights by floating plants.By adjusting the temperature or by offering plenty of live foods, the fish-keeper may stimulate breeding behavior.

 

 

Bog Wood

 

Congo Anubias

FRESHWATER HABITATS

THE PROPORTION of the fresh water fish in the world is very small -around two percent.Most of the world's water is in the oceans.But because of the diverse location , accessibility and differing qualities of fresh water , the variety of fresh water fish is vast.Fresh water fish can cope with a wide range of water locations, qualities ,temperature and this adaptability and resilience has made them hardy and very suitable for life in aquarium.


Types Of  The Fresh Water 

When water falls from clouds as rain, it is conditioned by the earth upon which it lands.This , in turns, effect the local fishes' tolerance of their water conditions.If water falls on granitic rock,its composition is altered very little and it remains soft.But when it permeates limestone,it absorbs calcium and make it alkaline and hard.Peaty soil will acidify water, as will the rotting vegetable typically found in slow-moving streams,including most aquarium fishes, such as barbs and rasboras,will, therefore ,tolerate acidify in their aquarium water.Lakes with no inflow or outflow of water from rivers,as in Rift Valley of Africa, have a high mineral content that must be emulated in captivity using commercial mixes.Estuarine waters are regularly altered by tidal additions sea water,and fishes from these environments , such as Mono and Scat, appreciate a small addition of salt in their water.By the time of rain water reaches the sea, it is of an entirely different composition.Once there, it evaporates and begins its journey back through the water cycle.

Rift Valley of East Africa

Effect Of  Temperature

Changes in temperate may also significantly alter fresh water habitats: where the volume of water is small, the differences between day and night temperatures is greater.More drastic fluctuations include the melting of mountain snows, which add cool water to rivers.

Fresh Water Of Mexico

Fish Food

FEEDING

The types and amount of food  offered to fish are crucial, as uneaten food will rot,upsetting tanks condition.Fish should never be feed more than they consume within a few minutes.Any food that is not eaten will simply left to waste,depleting the aquarium of vital oxygen.Fish will not starve if left for a week or so during vacations, providing they have been well feed beforehand.Fish foods fall in to two groups: dried or prepared foods and natural foods in the form of living creatures, seeds or fruits.Aim to match the wild diet of a fish as closely as possible.


DRY FOODS

Dry flakes

Multimillion-dollar businesses have been established to provide nutritionally balanced diet for all types of captive fish.Modern fish foods aim to closely match fish's natural diets.Whether fish are carnivorous , herbivorous or omnivorous , adults or fry, they are convenient foods available in several forms, including flakes, pellets,tablets, and liquids.In addition to proteins,carbohydrates and fats, fish require require vitamins and mineral just as humans do, and many manufacturers now add these during the production process.

Freeze-Dried  Brine Shrimp

 

Live Brine Shrimp

NATURAL LIVE FOODS

Mosquito Larve

Freezing and freeze-drying also means that live aquatic foods can be preserved.These are ideal, as living creatures, either waterborne or terrestrial , naturally contains all the nutrients that fish needs.They also make a welcome treat,if  offered only occasionally .Mosquito larvae can be collected from standing water, and bloodworms and water fleas are usually available from aquatic dealers.

Water Fleas

Fish Diseases

ONE ADVANTAGE of keeping fish is the small amount of time required for maintenance: a few minutes each day for feeding and perhaps an hour or so a week for cleaning.Periodic tests for water quality area advisable, especially with marine tanks, dedicated fish,or when breeding, but water hardness need not unduly worry the average keeper.

Fish diseases are usually initiated by stress, often caused by change in the aquarium enviroment or by pollution from over feeding or the decay of the carcasses of the dead fish.Fortunately, most ailments can be diagnosed, and many respond to medication or treatment .


TREATING COMMON AILMENTS


.White Spot:-  (Ichthyopthirius) Small white spots appear on the body and fins.It can be remedied with a commercial water treatment.The marine equivalent is Crptocaryon.


.Velvet:- Similar to white spot, but spots are smaller.All forms are caused by Oodinium parasites, which respond to treatment.


.Fungus:- (Saprolegnia)  The body has ''woolly'' growths; remedy with a salt bath, or , for freshwater fishes, a swab with a proprietary treatment.


.Mouth ''Fungus'':- This usually respond to antibiotics, which area available from a veterinarian.


.Skin and Gills Flukes:- Fish scratch against objects to relieve the irritation of skin flukes(Gyrodactylus).Gill flukes (dactylogyrus) cause fish to hang, with gills inflamed, at the surface.Commercial treatments are effective.



.Fin-Rot:- Often a secondary ailment due to acidic water, tissue between the fin rays is gradually eroded by bacteria.Changing the water may promt a recovery.


.Dropsy:- Scales stand out from the body and the fish becomes bloated;no cures are reliable , and fish are best destoryed.

Aquarium Setup

EVERYTHING that is placed inside a aquarium alters its balance, so every action of fish-keeper should be carefully considered.Fish needs plenty of space and oxygen, as well as carefully monitored feeding and water conditions.

CHOOSING A DEALER

A local aquarium shop is likely to share your water supply (and any related problems) , so there should be less stressed involved in establishing the fish in you tank.Try to monitor the shop's  fish stock over a period.Consider whether it has a fast turn because of brisk trade or because of stock is dying.Find


STOCKING LEVELS

A fish needs enough space to swim freely,but the size of the aquarium and the temperature of the water also effect oxygen content and will determine the  number of fish that can be held.The oxygen consumption of the four fish differs, partly because warm water fish carry less oxygen, so the recommended minimum size will differ accordingly.An aquarium measuring 24 in ((60 cm)) and 12 in (30cm) wide with a surface area of 28 in(square) ,(1800cm2), is roughly adequate for fresh water fish and all the marine fishes will consume proportionally more oxygen.

SURFACE AREA

The depth of the tank is not relevant to the oxygen content calculations;it is the surface area of the water that is important.Tropical marine species require 48 in^2  (300 cm^2) of water per inch (2.5 cm) of body length ; cold water fish require 30 in^2  (190 cm^2); and tropical freshwater fishes require 12 in^2 (75 cm^2) .The 24 in 12 (60x30 cm)  aquariums, therefore will hold  approximately 6 in (15 cm) of tropical marine fishes ( measured from snout to caudal peduncle ), 9 in ( 23 cm) of cold water freshwater fishes , and 24 in ( 60 cm) of tropical  freshwater fishes.

Fish Structure And Function

FISH have certain specialized function that enable them to survive them in water: gills instead of lungs, swim bladder to maintain buoyancy and the ''lateral line system'' to detect changes in the fish's surroundings by a form of echo location.


BREATHING

Fish ''breathe'' by drawing water in through the mouth and passing it over the gills.Oxygen in the water is absorbed by the gills filaments and then passed into the blood.Meanwhile, carbon dioxide and other waste are expelled.Some species have developed extra breathing organs for collecting oxygen in stagnating waters or in water with decaying plants, where oxygen levels are low.Members of the anabantid family , for example, have an auxilary organ near the gills that holds atmospheric gulped from the surface and extracts oxygen from it.The maze like organ has prompted the popular name of ''ladyrinth'' fishes.Some catfishes also gulp air and extract oxygen in a capillary-rich offshoot of the gut.

SWIM BLADDER 

Most fishes have gas-filled bladder that acts as a buoyancy compensation device, enabling them to maintain the position anywhere in the water.The bladder automatically infilates or deflates to give the fish neutral buoyancy ,equalizing the fish's weight with that if the surrounding water.Some fishes use their swim bladder to make or to amlify sounds.

THE GILLS

Gills absorb oxygen from water as it passes into the mouth and out through the gills cavity.

SIGHT AND SMELL

Sight is not important to fish as it is to humans, as many fish can navigate and locate in the darkest and murkiest waters by using their lateral line system to detect objects.A fish's eye do not needs eyelids because they are permenantly lubricated by the surrounding water.A fish's sense of smell is much more sensitive than a human, and a fish has taste buds , usually on barbels and fins.

LATERAL LINE SYSTEM

A fish's nervous system is linked to the outside world through perforations in single row of scales known as the lateral line.The single row runs horizontally along the length of the fish.Vibration caused by fish's own movement are reflected back from obstacles or by other fish and then detected by nerve endings deep inside the 'porholes' in the lateral line scales.

OSMOSIS

A fish's skin acts as a semipermeable membrane, or a one-way transfer system for water.Osmosis  causes the fluid to defuse through the membrane until there is unequal concentration on both sides of the membrane.The fluid of  freshwater fish's body is more concentrated than the liquid in which it lives.Thus, water constantly passes into the fish.To avoid bursting , freshwater fishes excrete as much watter as posssible and drink little.Conversely marine fishes loose water to the more concentrated sea water outside, and must drink constantly but excrete little.Few fish can pass from one type of water to other without distress.

FOOD-FINDING ORGANS

A fish's ability to taste food is aided by taste buds on the end of the barbels, such as those of the catfishes, and on the hair like cirri carried by blennies.Other fish ,notably the gouramies ,carry sensory cells on the tips of their pelvic  fins.

What Is A Fish?

Certain parrallel can be drawn between the structure of the fish and a human : both have a skeleton supporting  muscles and a heart that supply blood to all parts of body.A human's five senses are also present in the fish but are modified as required.However, the similarites end here, as fundamental changes occurred when life forms adapted to living on land.The greatest difference is in the fish's means of motion and maneuverability:fish are usually propelled by movements of tail stem ( caudal peduncle ), with the fins acting as stablizers.Nostrils  are used normally for smellling and play no part in respiration.Generally a fish's skin is protected by scales that reduce friction and protect the soft tissues from predators or parasites and even sunburn.The motion and shape of the fish's mouth depends on its feeding habit and dwelling level in the water.

FISH MOUTHS

Fish with upturn ( superior) mouths are surface feeders; a downturned (inferior) mouth facilitates feeding from the streams ; a mouth situated at the tip of the snout (terminal) often indicates a midwater feeder.

FISH COVERINGS 


The majority of scale types fall into two categories:ctenoid with small teeths on the rear edge ; and cycloid with smooth edges.Scutes are bony plates found on many catfishes.

EYE STRUCTURE

As fish eyes are carried on the sides of the head, fish do not have binocular vision and judement of distances is often inaccurate.Colours, however are preceived well.Focusing is achieved by movements of a fixed-shape lens,while in humans, it is the lens shape itself that is adjusted. 

FISH TAILS 

The shape of the caudal fin effect swimming performance and its colour may aid identification between species or providing cammouflage.The lyre-shaped and deeply cleft tails shown here facilitate speed.Bright patterns assit identification on the broad and crescent tails and sex differentiation on the round tails.Fins are cultivated for decoration only, and do not enhance function.