Understand the Principles of Aquatics Husbandry and Management UNIT 17 Understand the Principles of Aquatics Husbandry and Management

Three species Some facts and videos about the chosen species for your first assignment.

No. 1: Zebra Danios

Zebra danios Also called Zebrafish Name: Zebra danio (Danio rerio). Used to be called Brachydanio rerio Natural habitat: Himalayan streams also parts of India, Pakistan, Bangladesh, Nepal, and Burma. Now also found in canals, ditches, ponds, and rice paddies.

Zebra danios Diet: Omnivorous, primarily eating zooplankton, phytoplankton, insects and insect larvae, although they can eat a variety of other foods, such as worms and small crustaceans. Flakes and tubifex worms in the aquarium. Zooplankton: plankton consisting of small animals and the immature stages of larger animals. Phytoplankton: Microalgae similar to terrestrial plants in that they contain chlorophyll and require sunlight in order to live and grow. Tubifex: A small red annelid worm that lives in fresh water, partly buried in the mud. Annelid: A segmented worm of the phylum Annelida, such as an earthworm or leech.

Zebra danios Water Conditions: 17-24°C, pH 6.5-7.0 Size: Zebra danios can grow to 6.4 cm (2.5 in) in length (less in captivity). Numbers: Keep in shoals of six or more. Compatibility: Peaceful with other fish species in the aquarium. Watch out for long-tailed varieties...

Zebra danios Varieties: The so-called Leopard danio, is a spotted colour morph of the Zebra danio which arose due to a pigment mutation. Xanthid (pale-coloured) forms of both the zebra and leopard pattern have been line bred. So have long-finned types. In late 2003, transgenic zebrafish that express green, red, and yellow fluorescent proteins – GloFish - became commercially available in America. Transgenic: Relating to or denoting an organism that contains genetic material into which DNA from an unrelated organism has been artificially introduced.

GloFish

Zebra danios Fun facts and additional research Danios are being used in scientific research. A few “interesting” details of this would be a good way to enhance your assignments.

Zebra danio breeding You need a mix of males and females! Most males are slimmer, more active and have a more intense colouration. Most females ready to spawn are larger around the abdominal area and have white or pink colours there. Males are more enthusiastic about females with strong markings. Feed them up with lots of high protein foods – tubifex and brine shrimp are good.

Zebra danio breeding Set up a small breeding tank of 25 to 50 litres. Add conditioned water to half fill the tank. Add floating real or artificial plants. Fill the bottom with marbles or glass beads. Add a very gentle filter...

Zebra danio breeding Choose a good looking pair of fish and late at night add them to the breeding tank. They often spawn first thing in the morning so get up early... As many as 300 eggs are laid and they will fall between the glass beads, which stops the parents eating them... Remove the parent fish.

Zebra danio breeding The eggs should hatch within two days. They don’t need feeding until they’re free swimming. Then feed minute foods like paramecium, infusoria or a commercial fry food. Gradually wean them on to crumbled flake. Paramecium: A single-celled freshwater animal which has a characteristic slipper-like shape and is covered with cilia – tiny hairs. Infusoria: Microscopic organisms.

Zebra danio breeding https://www.youtube.com/watch?v=dQusbJhLZiw

No. 2 Platies

Both species are livebearers. No. 2 Platies Platy is the general name for two related species the Southern platyfish (Common platy, Moonfish or Mickey mouse platy) Xiphophorus maculatus and the Variatus platy Variable platyfish or Variegated platy Xiphophorus variatus. Most platies now sold in aquariums are hybrids of both species. (Salt and pepper platies, Tuxedo platy, Mickey mouse, Red Wagtail Platies, Red Platy, Red Tuxedo, Moon Fish, Topsail Rainbow, Sunset, Golden, Calico, Coral Red, Black, Blue,). Both species are livebearers. Platies come from the east coast of Central America and southern Mexico where they live in slow-moving waters - canals, ditches, and warm springs.  

No. 2 Platies Diet: Omnivorous – algae, plants and small crustaceans, insects, and annelid worms. Aquarium water: Keep in water at 7.0–8.0 pH, and a temperature range of 18 to 25°C. Compatibility and numbers: Platies are best kept in shoals with a minimum of two females (better three) to each male. Size: Females to 6cm 2.5 inches males 4cm 1.5 inches.

Fun facts and additional research No. 2 Platies Fun facts and additional research What’s the relationship between swordtails and platies? A few “interesting” details of this would be a good way to enhance your assignments.

Platy breeding

Platy breeding They are livebearers - babies can swim immediately after birth. Easy to breed. If you have both sexes they will breed. Females can store sperm and are often pregnant when you buy them. The parents and other fish will eat the young. Pregnant females develop a dark triangular shaped gravid spot near the anal vent which gets larger and darker as the pregnancy progresses. The female can then be isolated in a special trap or in a heavily planted aquarium. The young fish either escape the trap or hide in the plants. Remove the mother.

Platy breeding Female guppy showing gravid spot.

Platy breeding The female is placed in a trap and the baby fish escape through the slats. As the fry are fully formed you can feed them up on crumbled flake right from the start.

Platy breeding https://www.youtube.com/watch?v=bJC-DksOBsc

No. 3. Kribensis

No. 3. Kribensis Kribensis cichlid (Pelvicachromis pulcher) “Beautiful coloured tummy” Other common names: Red krib, Rainbow krib, Rainbow cichlid, Purple cichlid, Niger cichlid. Natural habitat: Southern Nigeria and Cameroon coast. Slow and fast-moving rivers among dense vegetation.

No. 3. Kribensis Temperature: 24°–26°C (75°–79°F). Water quality: Acid to neutral (pH 5.6–6.2), Kribs dig caves underneath plants for shelter and breeding and can be territorial. Diet: A study of wild Kribs showed that they were almost completely vegetarian eating diatoms, green algae, bits of plants and blue-green algae.

Differences male and female Kribs No. 3. Kribensis Differences male and female Kribs The Kribensis female is the more brightly-coloured. When ready to mate, she'll flirt with the male, shaking her body and showing off her vivid belly. She'll stay inside to guard the eggs - the male remains outside to guard the territory. Males are generally larger than females, growing up to 4ins/10cm long. Females reach 2.5/6cm. There is also a difference in their tails. A male's tail is pointed with a gold sheen, while a female's is rounded. Male dorsal fins are longer and more pointed, the female's is rounded.

No. 3. Kribensis Differences male and female Kribs. https://www.youtube.com/watch?v=DUbFyVK_HR0

No. 3 Kribensis Fun facts and additional research Kribs and some other cichlids will sometimes adopt fry from other parents. Why is this and what do they gain from it? A few “interesting” details of this would be a good way to enhance your assignments.

Kribensis breeding In the wild several females will pair up with one male (polygeny), but in the aquarium it’s more usual for two fish to pair. They need a cave to spawn in – up to 100 eggs are laid on the roof. In the wild, Kribs dig holes under plants. In an aquarium they’ll spawn in a flowerpot. The male and female guard the fry for up to a month.

Kribensis breeding Put a flower pot in a well-planted aquarium with plenty of gravel for digging. Gentle filter

Kribensis breeding https://www.youtube.com/watch?v=WAzHd4xxr_s