Update (Dec 2010) – sadly, the Native Fish Conservancy seems to have met an untimely end. The above link is via the Internet Archive. If any of the former webmaster/site managers are out there please feel free to make contact.

From the abstract:

The iron requirement of the guppy, Poecilia reticulata Peters, was determined by feeding them eight different levels of iron (0.0, 0.010, 0.020, 0.040, 0.080, 0.320, and 0.640 g/kg dry diet) for fifteen weeks. Growth and feed conversion was not significantly affected by the dietary iron. The red blood cell count, hemoglobin content, and hematocrit value was significantly reduced in fish fed an iron-deficient diet. Iron, copper and zinc content of the liver, spleen, kidney, blood, skin and muscle, heart, gills, and ovary was determined. The iron content was significantly lower in fish fed the iron-deficient diet while the copper content was significantly elevated. However, the zinc content in the organs was not affected by the levels of iron in the diets. the level of iron required by the guppy to prevent microcytic, hypochromic anemia was found to be 0.080 g/kg of diet.

Rocha explains some of the attractions of coral reefs:

The most striking feature of reef fish is their diversity, in terms of both species number and the range of morphologies. An estimated 4000 (18% of all living fishes) species of fish live on coral reefs and associated habitats of the Indo-Pacific and Atlantic oceans, and this number increases as new exploratory surveys are done.

Further examples of his reef fish photographs can be found at his online gallery. As might be expected from his scientific background, the photographs are not only beautiful, they are meticulously accurate.

They note there seems to be fewer and fewer clean bodies of fresh water for fish to live. Illegal deforestation, damming, and polluted water from factories represent a direct impact to the rivers and ponds the fish and plants called home. Some fish species are now declining at a very fast pace; some are feared already extinct.

The Siamensis Group’s ultimate goal is to make sure the continuous existence of Thai fish and plants. They believe that if people are aware of what aquatic life is in the water around them, they would like to protect it. The main part of their website is dedicated to reports from their survey trips. In the survey reports they note what species of fish and plants were found. If possible, they re-visit the location to collect more data and to update the current situation. Most of the reports are written in Thai, some English translations can be found at the bottom of the page. There are beautiful photographs on all pages, so even if you can’t read in Thai, the pages are well worth a look.

The Center produces a number of publications, including this ‘Manual for Commerical Production of the Gourami, Trichogaster trichopterus, a Temporary Paired Tank Spawner‘.

Gouramis are commonly known as labyrinth fishes. These fish are characterized primarily by an accessory breathing organ called the labyrinth organ. The labyrinth organ is located next to the gill cavities and is made up of folded membranes mounted on a bony frame. The delicate tissue has a high concentration of blood vessels and functions much like a terrestrial lung. If a labyrinth fish is denied access to the air it will drown because the gills alone will not provide sufficient oxygen to the fish.

This ‘lung’ adaptation is essential in the oxygen depleted waters that are home to gouramis. The image below shows typical Trichogaster habitat.

This report outlines how Ron Barnes tapped an abundant local supply of geothermally heated water and is commercially breeding thousands of african cichlids for the specialty tropical fish market on the U.S. West Coast and beyond.

A seasoned fisheries expert, Barnes earned a bachelor of science degree in marine biology from the University of California, Santa Barbara, and a masters in aquaculture from University of California Davis. He started out wholesaling tropical fish in Santa Cruz, CA, in 1988, before buying a small and remote (located near Merrill in the Lower Klamath Valley – about 10 miles south of Klamath Falls), tropical fish hatchery in 1990.

Barnes raises more than 100 different varieties of fish, including cichlids from Central America that also thrive in his alkaline geothermal water. He stocks no more than three species per pond to prevent interbreeding. Minnow traps are used to catch the bulk of the two-inch fish he sells, while a seine is used to catch larger fish and brood stock. Barnes and assistant Pete Booth perform all necessary chores at the year-round breeding and growing facilities.

The seahorse is the first of many marine fishes and invertebrates that the company would like to produce. Watercircle claim to be the first private company to be registered for captive breeding of seahorses in Singapore. Their seahorses are sold with their educational systems or exported with CITES certification.

Once plentiful, seahorses are now being exploited for Traditional Chinese Medicine and the ornamental fish trade. The numbers in the sea are getting smaller and apparently juveniles are being taken now that the numbers of adults are dwindling. The seahorse is a truly fascinating fish, there are many species, each with their peculiar traits, markings, habits, and docile behaviour. This makes them exceptionally attractive to the pet trade.

Watercircle have developed the SEAHORSERIUM? Marine Kit – a marine eco-system designed and packaged to give their captive bred seahorses a comfortable home. It is apparently easy to set up and makes an attractive aquarium.

Hopefully the big advantage of captive bred seahorses is they would be used to more commercially available foods. Seahorses are notoriously picky feeders, and finding shrimp, crabs etc the right size quickly becomes hard work for the average home aquarist. If a suitable supply of live food isn’t available wild caught seahorses are likely to go hungry, rather than eat something unfamiliar. Wild caught animals may carry parasites and may have been subjected to rough handling from capture, transport, dealer(s) before being introduced to the home aquarium. And of course, over-exploitation causes the availability of wild caught marine ornamental fishes to fall by the day.

According to Watercircle,
1. Their captive bred seahorses are easy to feed, weaned onto existing frozen fish food e.g. Hikari frozen shrimps.
2. They are also stronger, robust and disease free.
3. Able to withstand a range of salinity levels (18-34 ppt).
4. Sociable and friendly.
5. More active and live longer.
6. Able to adjust to various temperatures (20-30 degrees) for the tropical ones.