Photo of the Week: July 06, 2009

Hi Gang! 

This week’s POTW is a shot I took on a night beach dive in San Diego during a southern California “squid run”. Common squid (Loligo opalescens) usually inhabit the waters of the open sea but they venture into shallower, near shore water when they mate. During heavy squid runs, events that can last for weeks, uncountable numbers of common squid (aka market squid) come into the shallows. Mating typically occurs during winter months over areas such as coastal submarine canyons where the bottom is mostly sand and where deep water is nearby. Although there is some controversy regarding the belief that most mating occurs after sunset, many divers believe this to be the case. Mating activity occurs from the surface to the sea floor, depending upon conditions and the whims of the squid.

In this shot you can see a number of actively mating squid that are swimming over the whitish egg casings that have been planted in the sand by other females. 

As is the case with other squids, common squid are able to move forwards, backwards and sideways with amazing quickness and control. Movement is accomplished by coordinating the undulation of their fines with jets of water forced out of a directable siphon. When a male seeks out a mate he will try to latch onto her by grabbing her with his tentacles. As he does his tentacles often pulsate in a variety of reddish hues that are believed to serve as a warning to other potential suitors that this female has been claimed. When the male embraces a female he places a sperm packet under her mantle.

The price of mating is extremely high as both the males and females soon die. The females plant their whitish egg casings in the sand prior to their demise. Each egg casing contains approximately 200 squid eggs, and the casings are usually planted in large patches that seemingly transform the once sandy bottom into a shag carpet of egg casings.

Five days after the egg casings have been deposited the tiny red eyes of the unhatched squid can be seen, and the squid hatch in approximately two weeks. Upon hatching the young instinctively head for deeper water where over the course of their lives they are heavily sought after by many species of sharks, bony fishes, birds, dolphins, whales and more.

The presence of so many squid attracts numerous scavengers and predators that come to enjoy a natural feast as they feed on the dead and dying squid. The dying squid are an easy target for predators that range from rockfish to sea lions, harbor seals, pilot whales, dolphins and bat rays. Along the sea floor sea stars, lobsters and other scavengers feed upon squid that have already succumbed to their fate. Interestingly, the egg casings contain a protein that repels many potentials predators.

Diving during a squid run is exciting, and it can also be a little spooky the first time you experience a heavy run. Dive lights are “squid magnets” and the mollusks sometimes gather in such dense concentrations around dive lights and divers that it becomes impossible to see anything other than a mass of squid. But if you turn your dive light off or cover it with your hand the squid are likely to scatter in short order. Once you get comfortable with the idea of swimming around with squid in your face, under your arms, and in between your legs and fins you can enjoy a wonderful opportunity to see myriad animals and a phenomenon that provides rare insight into the inner workings of the California Pacific.

I took this week’s POTW with a 28mm lens on a film camera a few years ago while using Kodachrome 64 film. Interestingly, I recently read that Kodak will no longer make Kodachrome film.  Time moves on, but as the makers of Kodachrome used to tell us, the memories live on forever!

I hope you enjoy this week’s POTW.

See you next week!