Karl Aiken, Ph.D., Contributor

( L - R ) Fishers hold Diamondback squids caught in the fourth Diamondback squid catch last April. - photos by Takahiko Yasuda

A few years ago, if someone had said that there were Diamondback squids in Jamaican waters, it would have been greeted with polite laughter. Today, however, there is clear evidence to suggest that the species is indeed here.

But what exactly is the Diamond back squid? It belongs to a group of marine molluscs (the same group as snails and conch) which are called the Cephalopods (their name literally means the 'head-foot' group). These animals include the squids and cuttlefish and they are cousins as it were to the octopi, so they have relatively soft pulp-like cylindrical bodies with a circle of tentacles at one end.

The difference here is that the Diamondback squids are relatively large animals with an average weight of around 15 kg (or around 33 lb.) and measuring up to 1 metre (3 feet) in length . The proper name for them is Thysanoteuthis rhombus and another common name for them is the Barrel squid as their large plump bodies look a lot like a red barrel. But are they unique to this part of the Caribbean? Actually, they are found all around the tropics and even sub-tropics of the entire globe, but only at considerable depth. How deep is this you might ask? The average depth distribution of adults is around 1,500m or around 4,500 feet. In fact, they only become available to fishing gear when they approach around 500 m to reproduce.

Coming to jamaica

How did Jamaicans come to know about this squid? In 2004, the Japanese International Cooperative Agency (JICA)-funded Caribbean Fisheries Training Development Institute (CFTDI) in Trinidad and Tobago, conducted a workshop on Diamondback squid. Mr. Fujii of that institute first suggested that Diamondback squid could be found throughout the region at that time. JICA also conducted a deep-sea fishing workshop complete with fishing trials here in Jamaica that year with the Fisheries division of the Ministry of Agriculture and Lands, but there was no catch and no fisher requested special assistance with looking for diamondback squid.

By the end of 2004, JICA fisheries training staff attached to the Caribbean Maritime Institute (CMI), started holding more discussions on squid fishing with the Fisheries division and donated squid fishing gear to them. This equipment was loaned to the CMI, and using vessels owned both by the Fisheries division and by the CMI, there began a series of exploratory squid fishing expeditions. It was truly a cooperative venture as the University of the West Indies, Life Sciences Department's fisheries biologist Dr. Karl Aiken, working in conjunction with a marine ecologist from the Montego Bay Marine Park, along with CMI's JICA fisheries experts Takahiko Yasuda and other CMI staff, organised a series of trips to explore our coastal waters. This exploratory fishing was fully supported by the Fisheries division who promoted this effort to try to shift even some of the large number of fishers off the heavily fished reef fishery resources. The specially customised squid fishing gear was adapted from a successful Japanese design. At first there was no catch and things seemed fruitless.

Distinctive floating eggs

After this initial survey, a new series of trips began whereby fishers around the island were asked if they had observed the very distinctive floating eggs of the Diamondback squid over deep water. The team would then carry out exploratory fishing there. There were only two such locations found, each at opposite ends of the country. Using special gear, fishers from White Horses, St. Thomas and Whitehouse (Montego Bay), St. James along with the team of CMI experts caught two Diamondback squids in each of the areas mentioned previously.

The very first one was caught off St. Thomas in January, 2005. The average weight of the four Diamondback squids was 33 lb. or 15 kg. What is even more encouraging was that several even larger squid were seen to escape and fall off the gear near the surface. Therefore, next year some new larger and stronger gear will be deployed to try to catch these larger Diamondback squid. They make excellent sushi and other traditional Japanese dishes.

However, it is important to explain here that contrary to several articles appearing in the print media recently, it is presently much too early to say if this particular squid resource is a large or just a small one, as we have only caught four examples. Much more information needs to be gathered during 2007 before a proper scientifically - based decision can be made as to the size and status of the resource and importantly whether it is large enough to be sustainably utilised by Jamaican fishers. Queries about technical aspects of this subject can be sent to the following e-mail address: karl.aiken@uwimona.edu.jm

Prepared for the Mona Institute of Applied Sciences by K.A. Aiken, Ph.D., lecturer in Life Sciences.

Whitehorses fishers and members of the Japanese International Cooperative Agency pose with their catch - a Diamondback squid.