KARACHI: Fishermen on hunt for tuna along Balochistan’s coast recently released a giant diamondback squid that was found entangled in their fishing net, World Wide Fund for Nature-Pakistan (WWF-P) officials reported on Monday.

This is the second release of the same species by fishermen at sea for commercial operations; a 50cm long giant diamondback squid was released in March.

According to officials, on Sept 22 the large squid weighing around 18 kilograms was caught in the gillnet in the offshore waters of Ras Kachari, a headland located some 76 nautical miles west of Karachi along the Balochistan coast.

“Captain Saeed Zaman and his team carefully released the squid back into the sea after freeing it from the net. This is the second successful release of a giant squid within seven months,” WWF-P technical advisor on marine fisheries Mohammad Moazzam Khan said, adding that the squid was over three feet long.

The giant diamondback squid, he pointed out, was a species of rare occurrence in Pakistan and its release by fishermen was a good omen for the country’s fishery industry.

Fishermen trained by the organisation have released a number of species, some of them endangered, including whales, dolphins, whale sharks, mobula rays, sunfish, sea snakes and marine turtles that entangled in their nets, he said.

Senior director programmes at WWF-P Rab Nawaz said that the crew-based observer programme in Pakistan was a big success as it had not only led to collection of fishing data on tuna and tuna-like species, but had also provided valuable information about bycatch species as well and this helped save many marine animals accidentally caught in the nets.

“Given its success, many regional countries are considering initiating a similar programme for their fisheries,” he said.

Scientifically known as Thysanoteuthis rhombus, the giant diamondback squid is an oceanic species with a cosmopolitan distribution in warm tropical and subtropical open waters of the world, according to information available on the internet.

It has been reported in the Tsushima, Kuroshio, Agulhas, Brazil and the Gulf Stream currents, apart from its presence in the offshore waters of Pakistan.

The species propels itself slowly by gentle undulation of its long, broad, diamond-shaped fins. However, it is capable of a powerful reactive jet for a short duration when it faces a threat.

In the Arabian Sea, this species is of rare occurrence as it feeds on rich and dense concentrations of mesopelagic fishes (lantern fishes).

After its release, the giant squid released a dark pigment, which is an escape mechanism. The ink creates a dark, diffuse cloud which can obscure the predator’s view, allowing the cephalopod to make a rapid retreat by jetting away.

It is interesting that unlike most squids and cuttlefish, the ink released by the diamondback squid is reddish brown in colour.

This squid is also preyed upon by different species including dolphin fish, lancet fish, tuna, billfish, sharks and marine mammals (such as dolphins, rough-toothed dolphin, false killer whale and sperm whale).

It is not commercially harvested for most part, including in the Arabian Sea. However, there is a fishery of its range in some regions, especially in the Sea of Japan with an annual catch of about 5,000 metric tons.

This species is valued for its firm and tasty flesh, and its high commercial value makes it an important target species along the coastal waters of the Sea of Japan and around Okinawa.

Published in Dawn, September 27th, 2016