SQUIDDING is a growth industry among anglers.

Every year new, U-beaut squid jigs are heavily promoted by tackle shops on the internet: "So and so was fishing the inshore off Mt Martha and using (jig name and colour) caught his bag limit. "We have the new range in stock ... etc."

In my opinion this is a load of bunkum; a lure aimed at separating anglers from their dollars.

Squid jigs do work differently, but often due to colour, size or presentation more than any secret in the design.

My preference is for baited jigs rather than ultra-expensive brand names with their pearl bellies and fluoro backs.

I always have some imitation prawn jigs in my boat, for convenience only.

In February I wrote about sexing squid based on colour.

The problem with colour is that squid change colours almost as soon as they are lifted from the water.

Mind you, there is absolutely no reason to sort squid sex other than curiosity.

Several weeks ago, at the Queenscliff Marine Science Laboratories, I spoke to fisheries scientist Corey Green.

It turns out Corey has been studying for his PhD for three years and the subject of his studies are squid. A big subject given there are 650 known species of cephalopods in the oceans.

Corey has been studying squid population dynamics, variations and other topics beyond my comprehension.

I asked him about sexing squid and he said it was easy and had nothing to do with colour.

Turns out male and female squid are different anatomically.

Corey said male squid have a reproductive arm, called the hectocotylised arm.

This arm is on the right side underneath the squid's head.

It looks the same as the other arms except on the male squid the suckers do not run to the ends as they do on all other arms and those of females.

Instead the male arm has hair like appendages for about the last quarter of the arm's length.

These are used to carry sperm, and the male places the sperm inside the female squid with this arm.

I've caught some squid since speaking to Corey and the first thing I did was check their sex.

The arm is so distinctive that it was easy to tell the difference.

Calamari squid are mainly caught in our bays, arrow squid are an offshore species that sometimes comes into bays.

Corey said the combined recreation and commercial catch of calamari squid was about 150 tonnes a year. Of this about 50 per cent came from Port Phillip Bay, while Corner Inlet produced 32 per cent and Western Port 15 per cent.

There is a commercial quota of 2000 tonnes for arrow squid, which are harvested offshore.

The calamari rings many people enjoy are more likely to be arrow squid than calamari.

Arrow squid, in my opinion, is the most savage creature in our southern waters. Corey said this species was a born cannibal.

"It's survival of the fittest and these squid know they have to eat to survive," he said.

Which probably explains why, when the arrows are on the bite, if you leave one in the water on the jig, its relatives eat it; hook a barracouta when the arrows are around and chances are the same thing will happen.

Squid have three hearts and a single brain but on arrow squid the oesophagus passes through the centre of the brain.

You might think at that rate the squid should have disappeared but both species only live for about a year. In fact, Corey said the longest recorded lifespan of these squid is 291 days.

"Squid are fast growing," Corey said, "and arrow squid continue breeding throughout their lifespan while calamari spawning is restricted top a three-month period."

Anyone who has fished for squid from August to November in the Lonsdale Bight in Port Phillip Bay will know that the calamari deposit eggs among the seagrass. They are clear, look like clusters of jellybeans and take from 30-60 days to hatch.

Once born, squid grow at about 1mm a day.

Corey said arrow squid do things differently, and the eggs are kept inside a balloon-like structure that either floats or is carried around by the female.

Squid are a year-round proposition in our bays, it is a matter of knowing where they are.

Recent reports have anglers catching calamari in Cleeland Bight in Western Port, and in Port Phillip Bay good numbers are coming from Pt Cook, Frankston to Mornington, Portsea, St Leonards and Indented Head.

When I was a teenager squid were caught and sold for bait.

The only folk who ate squid were new Australians, and they must have been laughing all the way to the dinner table.

Nowadays you pay through the nose for squid and some of my die-hard angling mates have converted to the point they insist on keeping the tubes for the table and use the heads for bait.