by Eileen Ridgeway and Marco Lichtenberger
Introduction
The beautiful Takifugu ocellatus, otherwise known as the Orange saddleback puffer is a captivating fish. The one mystery that has always surrounded this beautiful puffer is how to lengthen its lifespan in captivity. Not much literature is available on the aquarium care of this species, and those surviving more than a few months in aquariums are scarce. I (Eileen) stumbled upon a revelation though, thanks to a little store Fugu that I brought home with me over 2 years ago.
Classification
Takifugu ocellatus is one of about 25 puffer species of the genus Takifugu, it was first described in 1758 by Linnè himself. The members of this genus might be re-classified as belonging to the genus Fugu in future scientific studies. Takifugu puffers mostly inhabit coastal waters in Southeastern and Eastern Asia. Several Takifugu species – among them the Orange saddleback puffer – are frequently found in freshwater streams and brackish estuaries during their mating time. However, their tolerance of freshwater is quite limited and was subject to several studies (see literature below).
The Orange saddleback puffer belongs to the smaller members of its genus typically reaching around 15 cm (6”). It has an olive green back and a white belly. A black band crosses the back of the puffer behind and above its pectoral fins, the dorsal fin lies in a black blotch. The black transverse band as well as the black blotch are bordered by strikingly orange lines. The eyes are orange, too.
A similar and likely closely related species is the Obscure puffer Takifugu obscurus. It was once seen as a subspecies of the Orange Saddleback Puffer, but the lines around its black markings are white to cream colored, not orange. The Obscure puffer grows to a larger size (40 cm, 16”), but otherwise shares a lot of common characters in terms of life style and needs in aquaculture with its Orange saddled cousin.
Natural occurrence and lifestyle
The Orange saddleback puffer is found along the coast of Southern China and Vietnam. It prefers muddy, silty and sandy bottoms in which it can quickly bury itself. While the breeding of many commonly traded puffers like the Green spotted puffer (Tetraodon nigroviridis) is practically unknown, the breeding of the Orange saddleback puffer is documented. Just like the Obscure puffer it migrates into larger rivers, especially the Yangtze River, China, each year from February to May. The puffers spawn in the rivers and return to the sea within a few weeks. This specific migration from saltwater to freshwater to spawn makes them so-called anadromous species like Salmon, while other fish like the Common eel are katadromous, they normally live in freshwater and migrate to the sea to spawn. The eggs of some Takifugu spp. need low salinities to hatch. The puffer larvae stay in the freshwater habitats for a few months, travel down the river as juveniles and return to the sea. Most growth takes place in the coastal, marine environment. When the Orange saddleback puffers reach sexual maturity, they return to the rivers each spring to spawn like their parents did. Females can be told apart from males at this time by the larger girth of their abdomen.
Takifugu ocellatus just like (probably) all puffers is toxic, but nonetheless it is a demanded food fish in China. Despite its small size it is often eaten and commands a high price due to its high quality meat. Naturally, the puffers have to be prepared by specifically trained chefs in order to avoid lethal intoxications.
In combination with overexploiting their populations, environmental pollution of the rivers has sadly resulted in declining numbers of this beautiful species. First projects to breed them in captivity with the use of hormones to induce spawning have been undertaken since 1997 and were successful at the Nanjing University. Aquaculture and breeding programs may hopefully help to maintain this species.
Aquarium Care
The Takifugu ocellatus found in the worldwide ornamental fish trade are wild caught specimens and so far do not come from the breeding facilities. They are mostly juveniles caught on their way from the rivers into the ocean and thus are often erroneously believed to be pure freshwater fish.
I (Eileen) found my specimen in a freshwater tank filled to the brim with other puffers and scats. He was incredibly erratic and just looked miserable. When I arrived home I immediately started acclimating him over to saltwater. He was very stable throughout the process and after about 7 hours, was home in his tank buried comfortably in a soft sand bed.
I then took it upon myself to find out as much as I could about this puffer to ensure that he has a long life. After speaking to various hobbyists that had kept them and reading whatever material I could get my hands on, I managed to collaborate a small amount of information that I could use for this endeavor. My one and only goal was keeping this fish alive.
Daily I checked parameters, tank temperature, salinity, flow, and everything else I could possibly think to document. I discovered during this time that my Fugu friend had a very voracious appetite and would feed almost like a wild lion, tearing into the meaty flesh of mussels and clams and shaking them violently. I was pleased at the progress he was making and he has held on strong even until this day.
During the past 2 years I have discovered what I believe to be the breaking revelation that could prolong and enhance this puffer’s life in captivity. Upon witnessing a massive import of these fish into America over the past 6 months I want to share what I have learned and documented to the public.
First things first, the majority of these fish sold in shops are going to be in fresh water or low end brackish water so you must be prepared to acclimate this fish over to its proper salinity. I recommend anywhere between 1.019 and 1.022. This process takes time and it cannot be rushed because it may be detrimental to the puffer’s health. This process should take anywhere from 7-10 hours.
Your Fugu’s home should be in a tank no smaller than 55 gallons as they have very erratic personalities and can potentially injure themselves by slamming into the sides of tanks. The substrate should be fine sand so that they can bury themselves in it. These puffers are lurkers and will spend a great deal of time hiding in the sand, only showing two orange eyes that scan the parameter.
Despite literature references (e.g. the Aqualog puffer book) claiming this species was peaceful, I do not recommend putting them in a tank with other puffers or other fish for that matter as it can cause unneeded stress and with the puffer’s aggressive behavior other tank mates will become a potential meal. Keeping several specimens together without territoriality problems may only be doable in very large systems of at least a few hundred gallons. The tanks used for breeding them in China hold more than 1,500 gallons.
Décor should be light and spaced out in the tank giving the puffer room to bury when needed and preventing him from knocking over anything that could trap him underneath. I would not recommend corals, again due to the erratic behavior of the puffer and there is a chance that he may eat them.
The temperature of the tank should not exceed 68 degrees Fahrenheit (20°C), and not to drop lower than 64.5 degrees (18°C), which also limits the use of commonly traded tank mates. These temperatures coincide with those used for breeding this species in China. Chillers are an item that will need to be purchased depending on climate and room temperature to keep this stable. Allowing the temperature to rise can be fatal to this puffer fish and it is critical to be prepared in the ways of temperature control before purchasing this fish. Your tank should also have a secure lid as these puffers have been known to launch themselves out of the water in a fright, which makes keeping the temperature low even more challenging.
I have found with this species that placing their tanks in an area of the home that is not frequented by visitors, traffic, children, or animals is best for them. They tend to get spooked easily and will go into a surge of flailing and slamming themselves into the sides and tops of the tank. Do make it a point though, to visit them daily and spend time with them to get them used to you as the owner and not completely against humans. Lighting is to be kept subtle and set on a timer for consistency. I run a 15 watt bulb in a shop light over the puffer tank for 6 hours every day. Every other day is acceptable as well if you choose as they seem to prefer a low lighted atmosphere.
Feeding your Fugu can be a stressful experience at first because the total move and acclimation can cause them to refuse to eat. Time and patience are the best method for this over all. Feed a varied diet of mussels, clams, shrimp, scallop, and other sea fare. Variation is the key to avoid deficiency diseases. Vitamins intended for pet fish use should be given in addition to the meals to help promote stronger immune systems.
Final Words
Consistency is key when caring for your Takifugu ocellatus. Following a strict schedule of water changes, parameter checks, temperature control and feeding will ensure that this fish will live a long life in his aquarium home. When choosing to become a Fugu owner, the best advice I can give is make sure you are prepared completely before bringing one home. Impulse buys for this fish will most always end in disaster. A complete tank set up, which can keep the low temperature needed for this species, should be cycled and ready for your fish the day you bring them home with you. Also, look for fish that have bright eyes, no skin abrasions or parasites, no torn fins and are active in the aquarium. Ask your local fish store what kind of water they have them in, what they have fed the puffers, if you can see them eat, how long they have been there. These answers are very important for you as a hobbyist to prepare for your Fugu and will give you the security that you are taking a fish friend home that will last a long time.
Literature
Abe, T. (1949): Taxonomic studies on the puffers (Tetraodontidae, Teleostei) from Japan and adjacent regions — V. Synopsis of the puffers from Japan and adjacent regions.- Bulletin of the Biogeographical Society of Japan 14 (13), 89-140.
Chen, Y.F. (2005): Induced ovulation and embryonic development of ocellated puffer, Takifugu ocellatus.- J. Appl. Ichthyol. 21, 136–140.
Ebert, k. (2001): Aqualog: The Puffers of Fresh and Brackish Waters, 96 pages.
Kato, A., Doi, H., Nakada, t., Sakai, H., Hirose, S. (2005): Takifugu obscurus is a euryhaline fugu species very close to Takifugu rubripes and suitable for studying osmoregulation.- BMC Physiology, 5:18.
Yang, Z. & Chen, Y. (2006): Salinity tolerance of embryos of obscure puffer Takifugu obscurus.- Aquaculture 2006, vol. 253, no1-4, pp. 393-397
Yuan, C.M. & Xie, H.G. (1986): Freshwater fishes of Jiangsu Province, China. Jiangsu Press of Science and Technology, Nanjing, China, p. 295–296 (in Chinese).