The human race is generally a bit, dare it be said, ‘uneducated’ with regards to the ocean and all that she holds. Leisure Boating will look at different ocean species every month with the aim of giving our readers a closer look at the wide range of life forms that lurk below.
Ask any angler what it is that tops their bucket list and they’ll most likely tell you that it’s catching a marlin, and asked to specify they’ll probably say Blue marlin. The king of all billfish, the Blue marlin is as majestic a big game fish as you’ll ever be lucky enough to see. With incredible speed, endurance, super strength and gorgeous surface acrobatics; you will never have a more exhilarating battle and the experience will remain with you forever.
It remains unclear whether the Atlantic Blue marlin and the Indo-Pacific Blue marlin should be classified as two separate species as their characteristics and features are nearly indistinguishable. Some taxonomists believe the two are closely related yet two separate species while others say that Pacific and Atlantic Blue marlin, although mostly isolated from each other, should be classed under one genus. For the sake of this article, however, we’ll treat them as one and the same.
What they look like
Blue marlin, like some of their other billfish cousins, can rapidly change colour in different circumstances but most often the back is cobalt blue to black while the flanks and belly are usually a silvery white. There may be light blue to lavender-coloured vertical stripes on both sides of the fish but they’re never as visible as on the Striped marlin and sometimes not at all.
Marlin have two dorsal fins and two anal fins which are supported by bony spines knows as rays. The pectoral fins are long and narrow and, along with the caudal fins and first anal fin, can be folded into grooves, streamlining the body and thereby reducing drag. The first dorsal fin membrane is usually dark blue while other fins are normally dark brown/black and the bases of the anal fins silvery white.
The body is covered with thick, bony, elongated scales and the characteristic bill is long and stout. Both the jaws and the palatines are covered with small file-like teeth.
Size matters
The Blue marlin is one of the largest bony fish in the ocean and, once fully matured, isn’t threatened by many other ocean creatures. As is the case with a few other game fish species, it is the females that grow largest. Males rarely exceed the 160 kg (350 lb) mark while female Blue marlin may reach weights of up to, and sometimes over, 500 kg and may grow to lengths of up to 5 m.
Seasoned marlin anglers will know the story of ‘Choy’s Monster’. It’s no tall tale, either. In 1970, Captain Cornelius Choy went out with a party of anglers off the coast of Oahu, Hawaii. The six people on board were holiday makers and none were experienced anglers so when they hooked into a truly massive fish, they took turns at the reel until Captain Choy eventually took over and brought the fish alongside the boat. It therefore cannot count as an IGFA record but the marlin landed that day is still the biggest caught on rod and reel. At 1 805 lb (820 kg!) it really was a colossus. Rumour has it they found a Yellowfin tuna of over 155 lb in its belly!
However, the largest Blue marlin caught in accordance with IGFA rules was landed in the Atlantic near Vitoria, Brazil in 1992 by Paulo Amorim and weighed in at 1 402 lb (636 kg).
Commercial fishermen, on the other hand, have landed much larger specimens. The largest Blue marlin caught in recent history is said to have been caught by a commercial boat and taken to Tsukiji market in Tokyo. It allegedly weighed a staggering 2 438 lb (1 106 kg)!
A ‘grander’ is the term given to any marlin over 1 000 lb (450 kg) and is considered an outstanding catch. Naturally, many anglers still pursue the biggest fish in their endeavour to break the record but scores of recreational fishermen target smaller species nowadays, fishing with lighter tackle and big game fly fishing gear.