Index Hide
- 1 Introduction:
- 2 Aggression
- 3 Power supply
- 4 Diseases
- 5 The fish in detail
Introduction:
The surgeonfishes, in English surgeonfishes, embrace 3 subfamilies, 6 genera and 72 species. They are all part of the order of Perciformes, suborder Acanthuroidei and family Acanthuridae.
Distribution of acanthurids in nature, Nasi brevirostris can be seen at the top in the blue, an Acanthurus sohal can be seen in the middle and the outline of an Acanthurus nigrofuscus can be seen below
In the aquarium they are particularly interesting for their beauty, simplicity of breeding, robustness and their scarce interest in any coral, be it small polyp, long polyp or soft, even if interest in some types has rarely been observed. of LPS.
All are characterized by being laterally compressed with a long dorsal fin, a small pronounced mouth, and a mobile spine (or immobile spines). All members of this family of fish are also characterized by having a very long intestines suitable for a purely vegetarian diet composed mainly of algae.
The 3 subfamilies are easily distinguished by the number and shape of the tail fins. The subfamily Nasinae has one or two fixed spines. The subfamily Prionurinae has 3 to 10 bony plates on the sides of the caudal peduncle.
While the most extensive and most interesting subfamily for the aquarist, the Acanthurinae, has a single spine on each side which remains adherent to the body and which can be extracted out of necessity as an instrument of offence or defence, the famous blade from which the expression ” surgeon fish”, and which can also be dangerous for humans.
Most of the 3 subfamilies live in the coral reef or in its immediate vicinity, usually in the warm climates of the Indian and Pacific oceans, as well as in the Caribbean and the Red Sea.
As previously mentioned, they are one of the most attractive families for aquarists, although every single genus has precise needs to be profitably raised, all genera need a lot of space for swimming and a purely vegetarian diet made up above all of the live algae present in the aquarium.
They also need crevices where they can hide if frightened. Being very active fish in swimming, they like strong currents and very oxygenated water, in fact, they can reach high speeds when swimming with their characteristic undulating motion.
For this reason, it is better to provide tanks that have one dimension strongly prevailing over the other rather than square tanks.
Aggression
They are often aggressive with similar ones, especially if they have similar liveries and colours, and above all if the aquarium is not enough to contain them both. Their aggressiveness increases above all after they have taken possession of the tank, making it difficult to introduce other fish, especially of similar size, after their complete adaptation.
It is therefore advisable to insert the surgeonfish only as the last fish in the aquarium, precisely to minimize these conflicts. It is highly discouraged to keep two specimens of the same genus in an aquarium unless you have an aquarium of truly adequate dimensions so that the fish can behave as in nature and therefore dodge and take a long swim to get away from their own kind.
Diet
Surgeonfish, as we have seen, have a very long intestines and therefore their diet must be composed largely of vegetables. After placing them in the aquarium, and once acclimatised, they will take care of most of the algae present (but not the cyanobacteria and rarely the already long filamentous ones!), in any case, it is good practice to supply them with algae even daily using clips to be able to hang them on the windows.
Excellent substitutes for commercial seaweed are the nori seaweeds found in the ethnic departments of supermarkets and used to prepare sushi. In addition to algae, it is important to use a complete and low-polluting feed, preferably granulated or microencapsulated, and if this is not accepted, it is advisable to add vitamins to the algae so as not to weaken the fish too much.
I advise against the use of lettuce, which is often recommended for these fish because it is mainly composed of water and therefore scarcely nutritious.
If poorly fed these fish can seek nourishment by nibbling especially the polyps of the SPS, this should not be seen as a normal feature of them but only as an intrinsic need to find food, the problem in fact tends to decrease when you return to feed them regularly.
Illnesses
Most surgeonfishes have a strong tendency to show symptoms of unease in the aquarium, generally due to a highly unsuitable biotope due to a too-small volume, lack of hiding places and lack of substrate on which to graze. The symptoms are generally expressed with the appearance of diseases due to protozoa, such as Oodinium and Cryptocarion irritants, which find the subject weak and therefore attack him.
Furthermore, the surgeonfish could become extremely aggressive, even leading to the death of weaker and shy fish or fish of similar livery, the beauty of these fish must not in fact be misleading, as they can become extremely bad if not properly housed. The best way to reverse these problems is to act on their causes,
I also advise against the widespread practice of buying a small fish because it “doesn’t grow” in the aquarium. The fact that the fish fails to develop in the aquarium only means that a pathology called induced dwarfism develops which will only aggravate the situations described above. It has also happened that several surgeonfish have literally died of lack of appetite for this reason.
Once all these problems have been circumvented, however, the surgeonfish remains a fascinating fish, a tireless swimmer that will become docile towards us, in fact, it is not uncommon to meet aquarists who can caress their surgeonfish (a practice obviously inadvisable in the long term due to the damage that our fingers they can cause to their mucous membrane).
Similarly, the fish also develops a strong intelligence which is expressed not only in the recognition of the owner but also in attracting attention with frequent tails of water especially when they are hungry.
A curiosity that unites all the centuries is that they tend to fade if frightened, if forced, or if in unsuitable environmental conditions, it is easy to observe in well-acclimatised fishes with strong colours, an indication of a good general condition when a new guest enters especially of similar shape and livery.
The fish in detail
The Achilles is certainly one of the most coveted surgeon fish. It is not always easy to find it in shops, and in any case, it is a very delicate fish in the acclimatization phase, after which, like all centuries, it becomes long-lived and resistant.
The splendid livery is certainly a reason for strong attraction in this fish, and the maximum dimensions it can reach as an adult recommend it also in relatively small tanks, around 400 litres, where in any case it needs to have a free space in which to swim undisturbed. The distinctive orange patch develops with adulthood.
- Maximum size: 24 cm
- Distribution area: Indian and Pacific Ocean
- Minimum tank size: 400 litres
- Temperature: 26-28°C
Acanthurus japonicus is one of the most interesting acanthurids because, due to its small size compared to other surgeonfishes, it can also be housed in sufficiently small tanks, around 300 litres. In any case, it is a fish that loves to be noticed and that loves to take possession of the tank in which it is housed, where it becomes very territorial. It is highly discouraged to host it with other similar fish, especially with A.
- Maximum size: 21 cm
- Distribution area: Pacific Ocean
- Reproduction time: 15 months
- Minimum tank size: 300 litres
- Temperature: 24-28°C
The Acanthurus leucosternon, also called white-throated surgeonfish due to its particular livery, is one of the most coveted surgeonfish. It is found quite easily, but it is not an easy fish to keep in an aquarium due to its characteristics.
In fact, in nature, there are specimens that reach 54 cm (although Scott W. Michael claims that they are no more than 23 cm) and therefore are ill-adapted to life in a small tank that does not allow them to swim sufficiently.
where they tend to become hyper-aggressive towards everyone. In fact, even in the wild, they are solitary fishes which govern a fairly large range and which do not digest the intrusions of others. The acclimatization period must be done very slowly and with great care as the fish is very delicate in this phase and subject to protozoan diseases.
In any tank you go to insert it will tend in a short time to become the absolute ruler, regardless of the other fish hosted, thanks to the strength of its swimming and its always covertly aggressive character. On the other hand, towards the aquarist the attitude is docile and it is often easy for him to have his back stroked, and to accept the food directly from the hands.
- Maximum size: 54 cm
- Distribution area: Indian Ocean
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 600 litres
- Temperature: 23-28°C
Among the centuries it is certainly the most herbivorous fish, the one which has the longest intestine and which therefore needs to be fed abundantly with algae, even several times a day, in order not to waste away, although it also gladly accepts small crustaceans. Always on the move, it has a poisonous sting that could cause panic even in people who come into contact with it.
Its fame over the centuries is that of being one of its most aggressive representatives, therefore it is highly discouraged to keep it with other acanthurids if not in extremely spacious tanks, a characteristic often found in aggressive surgeons is its need to have plenty of space for the I swim.
- Maximum size: 38 cm
- Distribution area: Indian and Pacific Oceans
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 700 litres
- Temperature: 24-30°C
The olive is a basically peaceful acanthurid but needs large spaces for swimming, as even in nature it loves to swim near the barrier and above the rocks. The difference in livery between the juvenile and the adult is very pronounced, with the juvenile livery much more appreciated, seeing that the adult livery tends to lose the yellow background in favour of a more anonymous grey background.
It can happen in captivity that the fish does not develop or that it arrives at the change of livery with a considerable delay compared to what happens in the wild.
Apart from the dimensions which recommend a fairly large tank, it is a docile and not very aggressive surgeonfish, so much so that it can be housed with other similar fish without any problems, provided that it is introduced first so as not to then have to fight against the status quo of another fish. In any case, it is certainly one of the simplest fish to acclimatise and is extremely long-lived.
- Maximum size: 35 cm
- Distribution area: Pacific Ocean
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 500 litres
- Temperature: 24-28°C
Also there. the provirus is a simple surgeon to keep in an aquarium, it is satisfied with relatively small tanks (around 350 litres) and is not aggressive by nature. Obviously, all the considerations made on surgeon fish are valid, from the need to have free space for swimming to the vegetable diet it needs.
A peculiar characteristic of this species, from which the English name mimic (mimetic) comes, is the fact that in the juvenile livery, it can strongly resemble the Centropyge flavissima or the Centropyge vroliki.
In the photo, you can see an example of juvenile livery.
- Maximum size: 25 cm
- Distribution area: Indian and Pacific Oceans
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 350 litres
- Temperature: 24-28°C
The Acanthurus sohal is a very coveted fish in the aquarium hobby, due to its stupendous livery and its tireless swimmer behaviour. Aggressive and territorial in nature, it often lives in large schools but always keep a safe distance from each other.
Even in relatively small aquariums, it tends to grow a lot and quickly, leading it to be very aggressive and intolerant. In the wild, it also usually attacks triggerfish and parrotfish to defend its territory. The tail fins are very thick and often also contain poison, making them an excellent defence and offensive weapon.
Without prejudice to these considerations, it is a simple fish to acclimatize and very long-lived, and easy to breed in captivity, of fundamental importance is only the need for large spaces. It is an excellent eater of green filamentous algae.
Coming almost exclusively from the Red Sea, it is fished with nets and adapts to water that is certainly warmer than average, even withstanding 30 degrees Celsius well. In reefs, it tends to live above the barrier itself and in the first meters of the sea.
- Maximum size: 40 cm
- Distribution area: Red Sea and Persian Gulf
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 800 litres
- Temperature: 24-30°C
The Naso brevirostris, often also referred to as Unicorn nose, is endemic to the Indo-Pacific area including the Red Sea. It reaches up to 60 cm and loves to swim in schools. Obviously, in an aquarium, it would need a tank specially created for it, not less than 1500 litres, also because it often finds itself living near the coral reef but immersed in the blue, where it is possible to see groups of about 25 specimens. The horn grows with age and becomes longer and longer.
It feeds on algae especially when young because as it grows it feeds mainly on zooplankton. Spawning by a pair has been observed several times in the wild.
Its nature is extremely peaceful and could therefore be a strong attraction for a particular aquarium, always of adequate size. Unfortunately, it is a fish that tends to jump out of the aquarium if the dimensions of the tank are not adequate.
- Maximum size: 60 cm
- Distribution area: Indian and Pacific Ocean, Red Sea
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 1200 litres
- Temperature: 24-28°C
The Naso elegans is endemic to the Red Sea and the Indian Ocean, even if sightings can be counted as far as Indonesia, for years it was considered the Indian variant of the Naso lituratus, from which it is distinguished by the colour of the caudal fin (yellow ) and for a more general chromatic variation, noteworthy are the moustaches that start from the tail and can be even several tens of centimetres long.
In the aquarium, it is a strong swimmer, like all the fishes of its subfamily, and it is an excellent eater of algae, including cluster algae such as valonia. It tends to be a docile and calm fish, but given its large size it tends to become aggressive in unsuitable tanks.
Those who have had the good fortune to see it live know that it is a fish which by its nature would be better left in the sea.
Even the Naso elegans tend to jump out of aquariums that are not large enough.
Naso elegans in the Red Sea, note the tail, impossible to see such a pronounced moustache in the aquarium
- Maximum size: 45 cm
- Distribution area: Indian Ocean and Red Sea
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 1000 litres
- Temperature: 24-30°C
Similarly to the speech made on the Naso elegans, the Naso lituratus has always been considered the main fish of which the first was a simple variety, this is because its range of belonging is much vaster and extends mainly over the entire Pacific Ocean from Japan to the Hawaiian Islands.
In the aquarium, it is a strong swimmer and is an excellent eater of algae, including cluster algae such as gallons. It tends to be a docile and calm fish, but given its large size it tends to become aggressive in unsuitable tanks. Those who have had the good fortune to see it live know that it is a fish which by its nature would be better left in the sea.
- Maximum size: 46 cm
- Distribution area: Eastern Indian Ocean and Pacific Ocean
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 1000 litres
- Temperature: 24-26°C
Paracanthurus hepatus is certainly one of the most common surgeonfish in the aquarium hobby, and its popularity skyrocketed after playing Dory in the movie “Finding Nemo”. Sociable and sympathetic fish with singular and very captivating behaviour.
He often sleeps on his side, often seems to argue with the glass of the aquarium and even pretends to be dead. In any case, he is a tireless swimmer. Less aggressive than the average surgeonfish, but very delicate especially when placed in the aquarium.
It suffers from very aggressive fishes and it is not recommended to keep it together with other surgeonfishes of similar livery with the Acanthurus leucosternon, while it mates well with the genus Zebrasoma, without prejudice to the size of the tank. As with most fish, it is advisable to introduce it young,
- Maximum size: 31 cm
- Distribution area: Indian and Pacific Oceans
- Reproduction time: 15 months
- Minimum tank dimensions: 400 litres
- Temperature: 24-26°C
Similar to the differences between Naso elegans and Naso lituratus, Zebrasoma veliger and Desjardins were considered the same fish for a long time. For some years, however, veliger has been considered endemic to the Pacific Ocean while Desjardins to the Indian Ocean and Red Sea.
In the Veliger the white stripes are much wider and more pronounced than in the Desjardins where instead the lighter dots that form the various streaks on the body predominate.
An excellent aquarium fish, apart from the size, as it is peaceful, simple to raise, and continuously looking for algae to graze, therefore it is strongly indicated for keeping the algal population of the tank under control, it has also been found in some specimens an interest in cluster algae such as valonia.
- Maximum size: 40 cm
- Distribution area: Indian Ocean and Red Sea
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 500 litres
- Temperature: 24-28°C
The Zebrasoma flavescens is certainly the most common surgeonfish and the one that best adapts to life in captivity. The reason is to be found in the fact that in nature it reaches a maximum size of 20 cm, and therefore manages to adapt and grow even in relatively small tanks (rarely less than 300 litres), and in the fact that it does not like the strong accelerations which instead characterize the subfamily Acanthurinae, but prefers a more placid swimming, characterized by the entry and exit of the ravines present.
If raised in small tanks it tends to be aggressive, not only towards the conspecifics but also towards all the inhabitants of the aquarium, although in the wild it is one of the subfamilies of the surgeon fish which loves to stay in groups. It is often subject to the disease of the black dots which generally highlights an incorrect diet, while it is subject to the diseases of the protozoa as explained in the introduction.
The characteristic of the flavescens is the almost complete discolouration that it assumes at night when it retires to sleep, an action that it generally performs inside a creek. At that moment it becomes almost totally faded and a white longitudinal spot emerges on the surface, all presumably for camouflage and to appear dead to the predators.
- Maximum size: 20 cm
- Distribution area: Central and South Pacific Ocean
- Reproduction time: 15 months
- Minimum tank size: 300 litres
- Temperature: 24-28°C
The Zebrasoma anthurium is the most aggressive of the genus Zebrasoma, even if it does not get to possess the typical aggressiveness of the acanthurids, it is in any case simple to keep in the tank and adapts very easily, like its other brothers it is a tireless devourer of algae, lives in groups and therefore is certainly more suitable to be kept in groups if the tank is large enough and if they are placed together, otherwise it is better to keep it as the only surgeonfish in the tank.
- Maximum size: 22 cm
- Distribution area: Red Sea
- Reproduction time: 15 months
- Minimum tank size: 400 litres
- Temperature: 24-28°C
Similar to the differences between Naso elegans and Naso lituratus, Zebrasoma veliger and Desjardins were considered the same fish for a long time. For some years, however, veliger has been considered endemic to the Pacific Ocean while Desjardins to the Indian Ocean and Red Sea.
In the Veliger, the white stripes are much wider and more pronounced than in the Desjardins where instead the lighter dots that form the various streaks on the body predominate. The specimen portrayed is still very young and the characteristics common to the two fish can be seen.
The veliger is a very resistant fish and very suitable for community life although with its size it would need a very large tank to favour it to the maximum
- Maximum size: 40 cm
- Distribution area: Eastern Indian Ocean and Pacific Ocean
- Reproduction time: 1.4-4.4 years
- Minimum tank size: 500 litres
- Temperature: 24-28°C
