Water Temperature and Fish Health

It’s important to keep our aquariums within a certain temperature range to make sure the fish and other aquatic creatures we keep are happy and healthy. Too high or too low, and our aquatic pets will suffer. The temperature range that’s best for each creature depends on what part of the world they’re native to. Tropical fish, for example, do best between 75° and 80°F, goldfish and other “cold-water” species prefer temperatures below 70°F, and temperate fish can be found in habitats that overlap tropical and cold-water realms.

Fish are cold-blooded – aka ectothermic or poikilothermic – animals, meaning they cannot control their body temperature. Instead, they rely on the temperature of their environment to regulate their metabolisms and activity levels. When it’s too cold, they’re less active, their appetite is reduced and their immune systems are compromised, making them more susceptible to disease.

When it’s too warm, their metabolisms and breathing speed up, and they use more oxygen. The problem is, as water warms up it holds less oxygen, which further stresses the fish. Once again, they become more susceptible to disease, and in extreme cases, they can experience organ damage or even suffocate. Making matters worse, above 90°F, the beneficial bacteria that maintain balance in an aquarium begin to die, creating the potential for dangerous ammonia and nitrite spikes.

In the Wild

Water temperature in nature isn’t always constant. In fact, it can fluctuate quite a bit. Some days are sunny, some are cloudy. There may be seasonal changes as you get further away from the equator. Sometimes it rains, which can cool things down considerably. The water near the surface is usually quite a bit warmer than just a few feet below. And what happens when the sun goes down at night?

There are two major differences between natural habitats and our aquariums when it comes to temperature. First, fish in the wild can usually move to a more desirable spot if they don’t like the temperature. And second, temperature changes tend to occur gradually in nature due to the massive volumes of water involved, so fish have time to adapt, or move. Not so in an aquarium.

In the Aquarium

Unlike nature, where water temperature can vary in different micro-habitats, the temperature in an aquarium tends to be uniform throughout the tank. Aquarium fish can’t move from a less favorable spot to one that’s more comfortable if the temperature is outside their preferred range. In addition, temperature changes are often more extreme and happen much more rapidly in an aquarium, giving our fish less time to adapt.

Fish that are kept at the wrong temperature long-term may not grow as large, their colors may be muted, they may be less inclined to breed, and they may not live as long. A sudden drop in temperature is often linked to the onset of Ick and other parasite outbreaks.

Maintaining Proper Temperature

Now that we understand how important maintaining proper water temperature is for our fish, let’s look at how to achieve it:

Avoid placing your aquarium near sunny windows, exterior doorways, heating and air conditioning vents, fireplaces and drafty areas that can affect water temperature.
Choose a quality heater that is designed for your tank size. (Large aquariums may require more than one heater.) Use the Aqueon Heater Guide to select the right size heater for your aquarium.
Make sure there is adequate circulation around your heater to ensure even heat distribution. (This will also prolong the life of the heater.)
Install an accurate thermometer and check it regularly to make sure your heater is maintaining the right temperature.
When performing water exchanges, match the temperature of replacement water as closely as possible to your aquarium.

Heating an aquarium is relatively straight-forward, but what happens when hot weather makes your aquarium too warm? Dialing the A/C down a few notches can be expensive, and what if you don’t have air conditioning? An easy solution is to open the tank lid and direct a fan across the water surface to create evaporative cooling. (Lower the water level slightly to prevent fish from jumping out.) Aquariums with cold-water fish or sensitive corals may require a chiller. For additional tips on cooling your aquarium, visit How to Keep Your Aquarium Cool in Summer Heat.

Mixing Different Fish

When stocking your aquarium, choose fish whose preferred temperature ranges match the temperature of your tank. Things can get a little tricky, however, when the upper limit of one species coincides with the lower limit of another. Trying to find a happy middle ground may stress both fish because one is always a little cold, and the other is a little warm. While they may tolerate the situation, neither of them will thrive. Always set your heater for the middle of your fishes’ preferred temperature range and choose fish that share the same temperature requirements.

Maintaining a stable temperature that matches your fishes’ needs isn’t difficult, and your fish will thank you for it!

Source: https://www.aqueon.com/

February 3, 2024February 3, 2024

Pygmy Corydoras

Pygmy Coriadorables!

Care Guide for Pygmy Corydoras – The World’s Tiniest Cory Catfish

Cory catfish are beloved in the freshwater aquarium hobby because of their happy-go-lucky nature and interesting behaviors, such as constantly shuffling through the substrate for snacks. While some hobbyists enjoy keeping the larger species, like the hognosed brochis (Corydoras multiradiatus) or emerald cory catfish (C. splendens), nano aquarium enthusiasts take special pleasure in finding the most petite corys. The pygmy cory (C. pygmaeus) has become quite popular because of its adorable appearance and unique swimming style. Learn about what it takes to care for one of the smallest corydoras in the world.

Pygmy cory perched on a plant leaf

What are Pygmy Cory Catfish?

This tiny South American schooling fish grows to a grand total of 1 inch (2.5 cm) in length, with females being slightly rounder and longer than males. Its silvery body with a horizontal, black stripe is not particularly colorful, but it’s hard to resist those big, black eyes and little whiskers that look like a mustache. Like many cory catfish, they like to “wink” by quickly looking down and will dart up to the water surface to take the occasional gulp of air. In contrast though, most corydoras are known as bottom dwellers, whereas pygmy corys have the unusual habit of hovering midwater by flapping their fins, almost like an underwater hummingbird.

What is the difference between the habrosus, hastatus, and pygmy cory? All three of these dwarf corydoras are similar in size and coloration. However, they have clear differences in their patterns that you can easily identify:

C. habrosus (salt and pepper cory): silvery body with an uneven, horizontal black stripe, a tail covered with stripes, and darker splotches on the head and back
C. hastatus (tail spot cory): silvery body with a big, black spot at the base of the tail that is flanked by small, white dots
C. pygmaeus (pygmy cory): silvery body with a thin, horizontal black stripe

Left to right: C. hasbrosus, C. hastatus, and C. pygmaeus

How to Set Up an Aquarium for Pygmy Corys

Pygmy corydoras were originally discovered in the river basins of Brazil, so they are used to pH of 6.4–7.5 and moderately soft water. They also appreciate slightly cooler temperatures between 72–78°F (22–26°C). In the wild, they are prone to predation and therefore like to hide amongst the tree roots and vegetation along the riverbanks. To make them feel more comfortable in your home aquarium, add plenty of plants and hardscape for cover. We often find them perched on anubias leaves and driftwood branches to give them a bird’s eye view of what’s going on in the tank.

How many pygmy corys should be kept together? While a small group could technically fit in a 5-gallon nano tank, they can be a bit shy. Instead, get a 10-gallon or larger aquarium so that you can keep a bigger school of at least 8–12 pygmies that will be less afraid to come out.

What fish can live with pygmy corydoras? Like most cory catfish, pygmy corys are very peaceful community fish that wouldn’t harm a fly. Because they are fairly petite, make sure not to pair them with anything big enough to eat them. Also, they are not the fastest eaters, so don’t let them get outcompeted for food during mealtimes. We find that they do well with other nano species — like neon tetras, chili rasboras, celestial pearl danios, otocinclus, and even a chill betta fish. Also, they won’t bother your snails or adult-sized dwarf shrimp, although they may accidentally slurp up a baby shrimp while foraging.

Pygmy corys swimming midwater with lambchop rasboras

What Do Pygmy Corydoras Eat?

As a species that hangs out in the lower half of the aquarium, they prefer to graze off the ground or on the surfaces of plant leaves. Their little, downturned mouths are most suited for eating sinking foods that are either tiny in size or soft enough to nibble on. For example, frozen bloodworms are often too hefty to easily swallow, but frozen daphnia, cyclops, and baby brine shrimp are perfectly bite-sized. In terms of dry foods, nano pellets, freeze-dried tubifex worm, and sinking wafers are all good options that have worked well for us. One of their favorite foods is Repashy gel food — whenever we drop in a chunk, they all seem to swarm on it like bees to honey.

How to Breed Pygmy Corydoras

While pygmy corys may not be as easy to breed as bronze or albino corys (C. aeneus), many hobbyists have had success with them in home aquariums. Take a mature, 10-gallon tank that is full of plants, mulm, and microfauna for the fry to feed on. Add a colony of at least six corys to increase your chances of having both males and females and feed them well. Be patience because it may take a little while for newly purchased corys to mature if you got them as juveniles. When the female is ready and full of eggs, she is often followed by an entourage of smaller males who are hoping to mate with her.

Unlike other corys that usually lay a cluster of eggs all in the same spot, the female pygmy will deposit a single, sticky egg — about 1 mm in diameter — on a strand of java moss or the roots of floating water sprite. Then she will swim to another location to place the next egg and repeat this process until tens of eggs have been laid. There are varying reports on whether or not the parents tend to eat their own eggs, but just in case, some breeders like to gently remove the eggs with their fingers and place them in a well-aerated spawning container. They may add a few drops of methylene blue, some alder cones, or even dwarf shrimp to clean off any fungal growth.

The eggs start off as translucent white and then eventually change colors. Fertilized eggs become a translucent yellow-tan, whereas unfertilized eggs turn solid white and should be removed to prevent fungus from spreading. Depending on the water temperature, the eggs usually hatch within 2–5 days, and the newborn fry have a translucent body, two black eyes, and a black band behind their head. Within a couple of days, they develop three more black dots down their back, which eventually become a fully mottled pattern all over the body to help with camouflage. Eventually, these splotches combine to form the classic black stripe running their lateral line. This rapid transformation happens within a month or so, such that the juveniles look just like miniature adults and can be hard to tell apart from their parents.

As with most babies of nano species, start off with nearly microscopic foods like vinegar eels, infusoria, and 5–50 micron golden pearls until they’re big enough to eat live baby brine shrimp and Repashy gel food. Provide frequent small meals and frequent small water changes to keep the water quality high.

Pygmy corys love laying their eggs in dense foliage like java moss.

Source: https://www.aquariumcoop.com/blogs/aquarium/pygmy-corydoras

February 2, 2024February 2, 2024

Chili Rasboras

Geographic distribution

This species is endemic to South East Asia, particularly to the Borneo island. Known to be located in the Indonesian province of Kalimantan Selatan, the Mosquito rasbora’s natural habitat consists of rivers, black water streams and swamps.

These bodies of water are usually tinted dark brown due to the tannins released from decaying organic matter like leaves, twigs and tree branches. This process gives the water an acidic property with a pH value as low as 4.0.

The fish thrives in densely vegetated areas and prefers a dimly lit environment, giving its shy behavior. In order for it to feel safe and comfortable in your home aquarium, you should try to replicate these conditions as much as possible.

Description

With its distinctive colors and pattern, the Mosquito rasbora displays an orange-red body color with a brown-black mid lateral stripe and a dark spot at the base of the caudal fin.

Behaviour

Because of its shy nature and very small size, this fish is not suitable for community tanks. You either keep it alone or with other small and peaceful fish like Strawberry rasbora or the Least rasbora.

Mosquito rasbora are a shoaling species and so it should be kept in groups of at least 10 members. Doing so will make them more comfortable in the aquarium environment.

Diet

In its natural habitat, the Mosquito rasbora is an avid micropredator, feeding on zooplankton, worms, small insects and crustaceans.

While not a picky eater, make sure to provide the Mosquito rasbora with a varied diet. Beside staple dried foods like flakes and pellets, the fish will reach its optimal form only if you feed it live food such as Tubifex, Artemia and microworms, on a regular basis.

Chopped-up bloodworms are also an option as long as the pieces are small enough for the fish to easily consume.

Feed once or twice a day and make sure the food is eaten in a short period of time, around 3-5 minutes as leftovers will usually reach the bottom and spoil the aquarium water.

Reproduction

Mosquito rasbora males are slimmer and slightly smaller than females. They also display brighter colors: dark red and black highlight on fins. This is especially observed when they’re in breeding form. They will compete with each other for female attention, becoming more aggresive and territorial. The dominant males in the group will also showcase a deeper red.

Females are bulkier and not as intensely colored. When they carry eggs you can easily notice their bellies becoming more round.

Upon reaching sexual maturity, they will lay eggs almost daily. The parents will attempt to eat the eggs if they spot them so it’s best to remove the pair once the spawning process is over.

If your goal is to keep as many fry as possible then the best approach is to separate the breeding fish into a smaller tank (10-20 liters). Add heavy vegetation to the tank. Java moss or any other kind of aquatic moss works best for this purpose.

Keep a small air-powered sponge filter to maintain water quality in the breeding tank. The temperature should be slightly higher than usual, around 27 – 28°C. If you want, you can condition the fish a couple of days prior the spawning, by feeding them quality fresh live foods.

Once the eggs are laid and fertilised, remove the adult fish from the breeding tank. After 24 hours the eggs will hatch and the fry will live off of their yolk sacs. Feed them infusoria and freshly hatched Artemia after another 24 hours.

Source: https://aquascapinglove.com/tropical-fish/boraras-brigittae/

January 29, 2024January 29, 2024

Anabantoids

Betta fish can breathe out of water…if they need to!

The anabantoids are also known as labyrinth fishes, which, unlike most other fishes, often do not rely primarily on the gills for respiration. The gills of labyrinth fishes are relatively small and primarily excrete the waste products ammonia and carbon dioxide. In fact, many labyrinth fishes are obligate air breathers, meaning they must breathe at the surface to survive. Other fishes have evolved a number of solutions to allow them to breathe air, including lungs and modifications to their gut and skin. Labyrinth fishes take their name from a specialized air-breathing structure called the labyrinth organ. Labyrinth fishes have paired chambers located above the gills which are extensions of the first gill arch. These chambers contain complex, folded, bony structures covered with respiratory epithelium (the labyrinth organ), allowing them to breathe air.
EVOLUTION, CULTURE, AND CARE FOR BETTA SPLENDENS
Craig Watson, Matthew DiMaggio, Jeffrey Hill, Quenton Tuckett, and Roy Yanong

Read more
https://edis.ifa s.ufl.edu/publication/FA212