Sailfin glassfish, Ambassis agrammus

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Neale Monks on the rarely seen Sailfin glassfish, Ambassis agrammus, from Papua New Guinea and Australia.

Common name: Ambassis agrammus

Scientific name: Sailfin Glassfish

Origin: Papua New Guinea and Australia

Size: Around 6.5 cm/2.5"

Diet: These fish are predators, and will eat a variety of invertebrates as well as smaller fish. Live bloodworms, daphnia, brine shrimp, and other such foods are most readily accepted, but they will also take frozen bloodworms and lobster eggs. Flake and pellet foods are ignored.

Aquarium: These fish inhabit both fresh and slightly brackish waters, so are very adaptable as far as water chemistry goes. Neutral to slightly hard and alkaline freshwater probably represents the ideal, but provided the specific gravity was kept below 1.005, these fish could easily be combined with low-end brackish water fish, such as mollies and gobies. Glassfish are fast, active fish, and appreciate open swimming space and a strong water current. As with other glassfish, they can be a bit feisty towards one another, especially if kept in insufficiently large groups, but otherwise they are peaceful, schooling fish well suited to community tanks. Has been bred in captivity, these fish are egg scatterers and lay their eggs among submerged vegetation. Sexual dimorphism is limited to differences in shape at spawning, the females becoming rather more rounded.

Identification: Similar to common glassfish, but with a distinctively tall dorsal fin and much larger scales on the flanks (the scales on common glassfish are practically invisible to the naked eye).

Availability: The specimens on sale at Wildwoods Water Gardens, Middlesex (0208 366 0243) are probably the first of their kind in the UK. However, quite a variety of unusual glassfish have become available in recent years, including the threadfin glassfish, Gymnochanda filamentosa, and the humphead glassfish, Parambassis pulcinella. Apart from differences in size, all glassfish can be kept in much the same way.

Price: Around 4-5 each.