Acanthocybium solandri

Distribution
Wahoo (Acanthocybium solandri) are in the family Scombridae, which includes mackerels, bonitos, and tunas. They inhabit tropical and subtropical waters of the Atlantic, Pacific, and Indian oceans including the Caribbean and Mediterranean seas. Wahoo prefer water temperatures between 21° and 30° Celsius. In Australia wahoo are found in waters north of Rottnest Island in Western Australia, along the Northern Territory and Queensland coasts and south to Montague Island in NSW.

They were first recorded off Tahiti, but it was the whalers and missionary settlers in the Hawaiian Islands that first fished for them. The fast and tasty fish were initially referred to as Ono, a Hawaiian term meaning good or delicious. Later, it was changed to wahoo, a variation in spelling from Oahu.

Size, Age, and Growth
The maximum reported size for the wahoo is 2.5 metres, with a maximum weight of 83 kg. Typically, individuals attain a size of 1 to 1.7 metres. After reaching a length of about 1 metre, individuals grow at a rate of 3-4 cm per month. Latitude appears to influence size, with average weight increasing with distance from the equator, correlating with cooler temperatures.

Reproduction
An average female may produce 60 million buoyant eggs per spawning. Size of wahoo at hatching is 2.5 mm. Little is known of the early life history of wahoo, however it is known that wahoo larvae are pelagic and prefer shallow water less than 100m in depth.

Characteristics
This near perfect example of a streamlined predator is among the fastest fish in the sea. The wahoo is pelagic, living in solitary or forming small, loose aggregations, with groups of up to 15 or 20 fish occasionally being seen. The body, covered with scales, is very long and slender. Wahoo are one of the few fish with a moving upper jaw. The teeth are triangular and finely serrated and the Jaws elongated to form an almost beak-like snout. The caudal peduncle is narrow and contains three sets of keels. Wahoo are very similar in shape to Spanish Mackerel but can be distinguished by their different jaw structure, the almost uniform length of the dorsal fin and the display of over 24 wavy cobalt-blue vertical bars over their silvery sides. Wahoo are a truly majestic fish when lit up in hunting or fighting mode. Their bars are most pronounced when the fish is first caught and fade swiftly after death. Get your photos quickly!

Despite the importance of wahoo as a sport fish, there is little information available on wahoo biology or population dynamics. Off the East and west coasts of Australia wahoo make a southern migration with the warm currents of late summer. This may indicate a spawning run as well. Off Coffs Harbour on the NSW North Coast I have seen them as early as February and as late as August.

Food Habits
Wahoo feed primarily upon other pelagic fishes, as well as squid. They have been recorded feeding on tunas, porcupinefishes, flyingfishes, dolphinfish, pilchards, scads, as well as many other species. Their streamlined body and great endurance allow them to pursue and overcome prey, which can be readily captured with their strong jaws. Wahoo have been recorded swimming at speeds of up to 21 meters per second in short bursts. (75kmh).

Predators
Sharks, including silvertips and makos feed on the wahoo. Other large predatory fish such as marlin have been reported feeding on wahoo. Bull sharks love to chase and eat speared wahoo if the fish is allowed to fight down deep. Try as much as possible to play the fish near the surface.

Importance to Humans
Traditionally, there have not been organised fisheries for wahoo, although it is favoured for human consumption. The incredible strength and speed of wahoo make them very popular as a gamefish by line fishers and spearfishers alike, especially in the US and Australia.

Safety Precautions
Wahoo have a scissor like jaw action with razor sharp teeth and can inflict a serious injury, so use extreme caution when handling or using a stabbing knife to stop them thrashing. They also have tremendous acceleration and enough power to drown you if you get caught up in your rig line. Keep the mandatory sharp knife handy at all times. If you use a hard float be aware that it may come into contact with the back of your head at up to 75km/h!!

Equipment
Big wahoo often tend to hang back at extreme speargun range and this coupled with the difficulty in judging size and distance in clear water and the potential to encounter other large gamefish, means that there are huge advantages in using a powerful, flat shooting, long range gun. I use a 1.4 metre Rob Allen Railgun with a 1.7metre 7mm shaft and powered by two 16mm rubbers. The gun is clipped off to about 15 metres of 200kg mono (eliminating the risk of spooking fish with a visible rig line) which in turn connects to 20 metres of good bungee terminating at an 11 litre foam filled Rob Allen float. Some divers prefer to use a breakaway head system when fishing for wahoo due to their scorching speed and soft flesh.

Technique
Wahoo may be encountered at surface level or down deep depending on a number of factors (time of day, fishing pressure, bait school depth). I find the best technique to be a neutrally buoyant hover at about ten metres depth, constantly scanning left to right and surface to bottom. More often than not you will see the fish glide in above you. I have found them more likely to be inquisitive if you are already submerged and this increases your odds of a successful stalk and shot. Wahoo often become shy if you duck dive down to intercept them within their sight. It is best not to chase wahoo but instead to try and move in on a converging course that will bring you within range.

Pick out an individual that looks like it may present a solid shot, squeeze off the trigger and get ready for the fastest acceleration you will ever see from a fish! It never ceases to amaze me how quickly your rig line will pass through your hands as your float throws a rooster tail into the air. Don’t put too much strain on the fish during its initial run or the head will tear through the wahoo’s soft flesh. If you feel that you placed the shot well and that the fish will hold then hang on and enjoy the tow. Just last year I hit a 23.5kg fish that pulled my float and I down to about ten metres and towed me horizontally for about fourty. One of the most thrilling captures I’ve ever made. The power to weight ratio of wahoo is amazing.
Fortunately they can’t keep up this sort of performance indefinitely and if you’ve managed a good shot and held them for the first few minutes there is a good chance you’ll land the fish.

Where to fish
Try wherever there is a suitable current of the right temperature, usually offshore or along the edges of deep water rocks, bomies or pinnacles. As with all gamefish, wahoo are attracted to features that hold prey species. This includes rocks, wrecks, reefs, floating debris, current lines, temperature changes in the open ocean and bottom variances that create current upwellings. A good starting point is to position yourself on the outer edge of the bait on the upcurrent side of the feature in waters exceeding 25 metres depth. Predators will usually patrol past every so often and you must be patient enough to wait for this to happen. Where there are no features to concentrate prey species wahoo will be few and far between. They are often encountered while fishing for other pelagic species, such as dolphin fish, assorted tunas, sailfish, marlin and spanish mackerel.

When to fish
Water temperature is important and, provided it is right, the Wahoo can appear at any time. They are more likely to be seen closer to the surface in the morning and the late afternoon, generally appearing deeper down during the middle of the day. I have also found that wahoo are much easier to approach early morning and late afternoon.

Eating
Wahoo are excellent table fish, provided that they are bled and cleaned soon after capture and put on ice as soon as possible. Steak out the fish and then cut out the eyes of the steak. Wrap in bacon, sprinkle with lemon pepper, and put on the grill. The meat is flaky and the taste equal to tuna. This fish has been linked to ciguatera poisoning from human consumption of its flesh so be careful with overly large specimens from tropical locations. Wahoo do not last well in the freezer and should be consumed within a couple of months of capture.

Records
The current Australian spearfishing record is a wahoo of 37.75kg taken by Brett Machen at Flat Rock near Stradbroke Island in 1998. The current IUSA world spearfishing record is a fish of 56.699kgs taken by Bruce Gaudino in Mexico 2002. According to the International Game Fish Association (IGFA), the all-tackle record for wahoo is 71.89 kg taken in Baja, CA, USA - 10 June, 1996.

Legalities
Legislation of course varies from State to State and Country to Country so check with the relevant Authorities before setting out after Wahoo. Remember that Fisheries legislation is regularly updated so check the relevant Agency website to keep up to speed with the latest rules.

NSW, Australia - A maximum bag limit of 5 fish per person applies. As a result of the NSW Recreational Fishing License a number of Fish Attracting Devices are being deployed off the NSW coast and these will provide great habitat for wahoo.

Conclusion
With the increasing interest in bluewater hunting, the exploration of new spearfishing locations and ongoing improvements in equipment and technique many more divers are encountering or becoming aware of wahoo. In many places today they are a prized and consistent catch when just a few years ago it was a rare event for a spearfisher to even see one. Do a little research, track down a likely location and you may even find a little slice of wahoo heaven for yourself!