Daphnia magna is probably the most common species in the aquarium hobby. It has been a favourite live food source since the hobby began. Daphnia magna are the largest member of the Daphnia family with males reaching 2 mm in length and females in the 3 – 5 mm range. They vary in color from a pale yellow to salmon-pink, and this is typically affected by their food source. Daphnia magna has a wide temperature tolerance, but favor cooler temperatures between 64°F / 18°C and 72°F / 22°C.
The life span of Daphnia, from the release of the egg into the brood chamber until the death of the adult, is highly variable depending on the species and environmental conditions (Pennak, 1978). Generally the life span increases as temperature decreases, due to lowered metabolic activity. The average life span of D. magna is about 40 days at 77°F / 25°C and about 56 days at 68°F / 20°C.
The nutritional content of Daphnia varies considerably depending on their age and the type of food they are receiving. Although variable, protein content usually averages 50% of the dry weight. Adults normally have a higher fat content than juveniles. The total amount of fat per dry weight is 20 – 27% for adult females and 4 – 6% for juveniles.
The Hypancistrus Zebra comes from the Rio Xingú river in South America. The Rio Xingú flows through Brazil and then into the mighty Amazon river.
The area of the Rio Xingú where this fish lives in the wild is full of different sized rocks with some fine sand on the river bottom.
Size
80mm (3.1 inches). Standard Length
Comments
If these guys were not so shy, they could easily be one of my favorite aquarium fish!
Care Info
For a rare and beautiful fish, Hypancistrus Zebra is not demanding to keep. They like to be warm with water temperatures in the mid 80’s, and they enjoy meaty foods rather than a diet of plant material.
Spawning Info
My fish are too young to spawn, so I have no first hand info.
Moina are are the smallest member of the daphnia family. Adult Moina (700-1,000 µm) are longer than newly-hatched brine shrimp (500 µm) and approximately two to three times the length of adult rotifers. Young Moina (less than 400 µm), however, are approximately the same size or only slightly larger than adult rotifers and smaller than newly-hatched brine shrimp.
Under optimum conditions, Moina reproduce at only 4-7 days of age, with a brood size of 4 – 22 per female. Broods are produced every 1.5 – 2.0 days, with most females producing 2 – 6 broods during their lifetime.
The nutritional content of Daphnia varies considerably depending on their age and the type of food they are receiving. Although variable, the protein content of Moina usually averages 50% of the dry weight. Adults normally have a higher fat content than juveniles. The total amount of fat per dry weight is 20 – 27% for adult females and 4 – 6% for juveniles. That said, Moina are generally believed to have a higher protein content, often as high as 70% protein.
Danio xxx were first collected in xxxx in south-western Thailand by Mr. A. F. G. Kerr and are named in his honor in 1931 by H.M. Smith when the fish were officially described.
The species was described from fish collected in a hill stream, Koh Yao Yai (island), Phuket, Thailand. They are also known to be found in similar habitat in the Malay Peninsula from southern Thailand (Krabi and Ranong provinces) to Malaysia. The species has also been found on the other islands in the area including Phuket, Ko Lanta and Langkawi.
These fish typically inhabit submontane streams to hillstreams in forest areas and small rivers typified by very clear water with substrates of rocks, boulders and gravel.
Size
xxmm (xx inches). Standard Length
Comments
One of my favorite Danios!
Care Info
Like a good many of the other Danios, these fish are very hardy and undemanding in the aquarium.
