The Marine Betta as it is commonly known is often overlooked by reef keepers. Whether that is due to its predatory nature or its shy disposition is anyone's guess! This wonderful fish is not only a stunning sight to behold, but also a superb addition to most reef tanks. A calm and seemingly wise attitude makes the Marine Betta an endearing member of the reef.

Size	Up to eight inches in captivity
Location	Throughout the Indo-west Pacific, North-western Australia and the Great Barrier Reef
Compatibility	Careful selection of tank-mates is necessary
Tank Conditions	Subdued lighting, plenty of hiding places and at least 80 gallons
Feeding	Can be difficult, may need live food to start
Breeding	Possible in captivity
Availability	Frequently available, both wild and captive bred
Cost	From £35 up to £80 for adults

More subdued tank-mates will allow the Marine Betta to explore its surroundings in daylight hours to a greater degree since this is not a particularly fast moving or aggressive fish. Ideal tank-mates could include Cardinals, Chromis, and other placid fish. Care must be taken when placing this fish in a tank with smaller fish, crabs and shrimp, as these are their prey and anything small enough to fit inside their cavernous mouths will not likely last the night!

Thought must also be given to flow in the tank, since the Marine Betta is generally found in deeper waters where water movement is much less than that of the reef-crest. If you observe a Marine Betta move you will notice that they are not particularly strong swimmers - their large fins are delicate and do not aid in swift movement, so your consideration is needed here.

As mentioned, the Marine Betta is generally found in deeper waters (up to 45m), hence less flow, but also less light. As you can see from looking at the Marine Betta, it has large, well developed eyes which allow a greater amount of light to fall on the retina and this gives them the advantage of being able to see their prey at night. So, now we know they have big eyes and the reasons why, what can we do to help if you're thinking of buying one? Well, you can take into account the fact that they will be less active in a brightly lit aquarium with high flow, and make sure (as said before) that you don't have any small fish or invertebrates in your tank which could be prey to the Marine Betta!

Since the Marine Betta is not a massively active fish it requires a significantly smaller tank than may have been thought when noting its possible adult size. The generally recommended tank size for this fish is around 50 gallons; however, I would not recommend a tank volume of less than 80 gallons. This is due to my experience of this fish being more active than most suggest, and the knowledge that as filtration methods evolve and develop, more fish are able to be placed in a smaller capacity of water and the use of live rock needed is minimal. Since the Marine Betta spends a large amount of time out of sight in the cracks and crevices of the rock structure, it needs larger amounts of secluded space in order for it to spend more time out in the open. Bear in mind that the more hiding places you provide, the safer it will feel and therefore the more likely you are to see it.

The Marine Betta posses a false eye spot on its caudal fin which not only adds to its beauty, but also serves as a useful deterrent against its predators. The eye spot has been suggested to mimic a moray eels head when combined with the way in which the Marine Betta attempts to deter predators or even the reef keeper! This characteristic involves the fish swimming into a crevice and leaving only the caudal tail and eye spot on display. At lower depths and for fish with poorer eyesight it is understandable to assume that this would look remarkably like a moray eel, which is generally not considered as prey!

Now we come to one of the most important and also interesting sections of the article, the feeding! Firstly, the Marine Betta can be tricky to get to feed in the average aquarium since they can be very picky and are relatively shy creatures. So, dumping frozen or pellet food in the tank will likely scare them back into hiding, so a less direct way of feeding is often needed. Common foods to feed these fish are live river shrimp and brine shrimp; although these contain particularly low levels of nutrition they do appear to stimulate a better feeding response. My experience has been that Marine Betta will eat frozen food, but that it may take some time for them to be converted, so a mix of both live and frozen is suggested. Mysid shrimp seem to be their food of choice. From observation, they tend not to be as finicky as has been portrayed, but they are slow feeders, meticulously selecting particular food items, then watching them for a few seconds, and finally eating them. Due to this they can be easily out-competed by fast mover, less selective fish.

The natural feeding techniques which can be observed with live river shrimp are incredibly interesting. It involves the fish slowly gliding through the water column to the sand bed, then presenting itself quite close to the shrimp - opening all fins completely, moving its entire body into a crescent shape around the prey, before moving back and forth (whilst retaining it's posture), then quickly moving it's head towards the shrimp and opening it's cavernous mouth to swallow the shrimp, then swiftly retreat back to it's crevice to digest in peace!

Having witnessed this many times I now believe that the crescent shape and the moving back and forth are very important aspects of feeding. The crescent shape, I believe, is aimed to draw the prey's attention to the fish's eye spot (since their actual eye is camouflaged with the rest of the body), which means that the prey's focus is not on the actual eye, and therefore not the end it will be eaten by! This means that the prey item is less likely to realise that they are about to be eaten, which is not only interesting to watch, but also a superb use of a false eye spot!

The sexing of this beautiful fish is difficult to say the least, however, after some research and talking to someone who helped breed them on a commercial scale, I found that one of the only differences were the size and number of white spots on their body, head and fins. The males generally have a greater number of smaller white dots, whilst the females tend to have less dots of a larger size. However, this rule is not steadfast; it is merely a common observation of both myself and the previously mentioned breeder. Sexing is difficult due to the lack of sexual dimorphism, and please be aware that adding two fish of the same sex may lead to aggressiveness unless in an extremely large tank with sufficient hiding places.

Breeding is relatively easy, with this species being raised in captivity many times; a quick search will provide masses of information. Breeding is rough and will normally result in torn fins. The egg ball, which is around an inch in diameter and contains about 500 eggs, will be deposited by the female on the underside of an overhanging rock, where after around 5-6 days they will hatch. The fry have only a very small egg sack and so can be expected to eat quickly after hatching when compared to other fish. They grow relatively slowly, changing colour until around seven months old when they gain their adult colouration.

The availability of the Marine Betta varies greatly, and the depth and beauty of this fish is a negotiating factor in its price. Wild-caught Betta are becoming more common now, although captive bred Bettas are more readily available. They will usually cost from around £35 to £65, but for a large adult expect to pay around £80. Don't let the price tag put you off though, if you want a beautiful, handsome, endearing fish to admire that you don't mind giving extra care to despite not seeing it quite as often as you'd like, this is the fish for you. A truly worthy addition to any reef tank and reef keeper worth their salt!