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Saturday 29 October 2016

10) Damselfish

Dascyllus melanurus
One of the most popular families of fish to be seen in hobbyist tanks are the anemonefishes and damselfishes, the Pomacentridae. Closely related to the almost entirely freshwater cichlids, they have very similar breeding behaviour, with one or both of the breeding pair guarding a nest of eggs laid on the substrate until the eggs hatch. The main difference from cichlids is that damselfish larvae are much smaller and disperse immediately into the plankton on hatching, whereas most cichlids engage in long term care of the fry.

Friday 21 October 2016

9) Foxface rabbitfish

S.vulpinus - day
One of the great mysteries of this fish is its name. It has a strong head pattern, but it is vastly more like that of a badger than a fox or rabbit. If anyone can give a reason for this, please leave a note in the comments. The face pattern may be aposematic – it has powerful venom glands associated with the dorsal fin spines and can give a painful sting.Another feature of this species is that it changes colour at night, which helps it blend in with the background and avoid predation.

Friday 14 October 2016

8) A variety of tangs

P.hepatus
 Currently one of the most popular animated films is Finding Dory, and as might be expected the actual fish is invariably greeted by that name by children visiting the aquarium. As well as Dory (technically a Pacific Blue Tang Paracanthurus hepatus), there are four other tang species to be seen in the large marine tank.

Friday 7 October 2016

7) Shotsilk Goby

P.zebra
Despite its name, the Shotsilk Goby Ptereleotris zebra is not a true goby at all, but rather a dartfish in the family Microdesmidae. There are around 20 species in all in the genus, with numerous other genera, mostly in the tropical Pacific and Indian oceans. They are all elongated fish with often eel-like bodies, and most live in burrows or other concealed locations. Some enter brackish water, and at least one, Pterocerdale from Queensland, Australia, appears to be a freshwater species. The English name refers to the iridescent fabric called shot silk, which refers to their shimmering colours. Several other species of dartfish are also seen in the aquarium trade, but at present all are wild caught – there is no commercial propagation of these fish.

Tuesday 4 October 2016

Aquarium 6: Batfish

P.orbicularis adult
 Among the reef fish in the big tank are a small shoal of juvenile Orbiculate Batfish, Platax orbicularis. Superficially similar to the well known freshwater aquarium angelfish (which was originally described as a Platax), they belong to a group of mostly monochrome, large tropical marine fish commonly referred to as spadefishes. As juveniles they have very tall dorsal and anal fins, which combined with a circular, compressed body gives a triangular body shape. As they mature their fins become proportionally smaller, with a more rectangular body shape. They are all fairly large fish, with some species growing to over 70cm