You know how I love me some developing squid... Here is some before and after shots of the common market squid.

You can see that baby still in the capsule with the yolk coming out from the tentacles. When the squid is ready to hatch, the capsule and the chorion (which surrounds the embryo) are greatly thinned. However, they still present a considerable barrier. Squids have a hatching gland, called the organ of Hoyle, which produces an enzyme that dissolves the chorion and the capsule wall.


Here's a nice quick shot of a post-hatch baby. You can see some of the chromatophores, pigment-containing cells, as black dots on their body.



To round off this post, I thought I'd close with a video of those chromatophores in action!

Story of a black jelly

Last summer we had a rare event. Tens of black sea nettles (Chrysaora achlyos) washed ashore on our beach. These guys are pretty rare, so we jumped at the chance to get some gonadal tissue to start a new culture of jellies. We collected the adults from the beach, and I extracted the gonadal tissue from the insides of the bell. (This was a rather painful process which involved me getting stung for three days.)

I used bits of the tissue to sex the animals; females had eggs, and males had packets of sperm. After I figured out who was what, I put a little bit of male gonads and female gonads together in a petri dish and mixed them up, to beak open the male's sperm packets. (It felt a bit like making red scrambled eggs.)

Male sperm packets

Female tissue with eggs

After 3 days, planulae were spotted swimming in the petri dishes.


After 5 days, the planulae settled to the bottom to become polyps. These are newly settled with only 2 fully formed tentacles.


Four months later, I am very happy to say that my polyps have begun to strobilate. I have some beautiful ephyrea, that will become (in my opinion) the prettiest-colored jellies ever.

Bringing in the new year

This new year's day has been pretty exciting because for the first time ever, we still have baby California spiny lobsters in our care. This little guy was 184 days old, about 14 days older than last year's record. He was also a little smaller than a quarter, all stretched out.

Larval lobsters can remain in the plankton for up to a year, so we still have a way to go before it settles and looks anything like the lobsters we know. This year, we've seen some growth that we've never seen before, new legs and tail sectioning, and it's mostly due to a difference in the diet we're feeding them.


Here's hoping that they continue to grow in the new year!

Anatomy of an electric ray

I love my job. Sometimes I just get to participate in (or watch) cool stuff. As was the case a week ago, when I learned that we were going to be dissecting an electric ray.

This electric ray had been brought in by a fisherman, who didn't want to eat it or let it go to waste. So we decided to hold a public dissection, so that we could learn more about it. We also preserved some of the pieces for our collection, to be used for later research or teaching.


Electric rays are slow-moving rays that live off of the pacific cost, in cool waters. They don't have a stinger, but do have a specialized organ that produces electricity, which they use to capture food and defend themselves.

In this picture you can see the two-chambered heart, center, at the right most edge of the cut. Below that (center) is the stomach. To either side of the stomach are two very large livers. Like all sharks and rays, the electric ray lacks a swim bladder and depends on the oil reserves in the liver to help maintain buoyancy. The large green ball near the upper liver lobe is the gall bladder.


This is a nice close-up of the electric producing organ. Basically, it is little more than coin shaped muscle stacks. Since muscles produce electricity, the arrangement of muscle tissue in this configuration helps optimize the amount of electricity produced in the area. By having an organ on either side of the body, the electric ray can stun prey trapped between the two sides of their fins.

Slime star

This is Pteraster tesselatus, commonly known as a slime star. As its name implies, when disturbed this star can produce copious amounts of slime, which may protect it from predators [1]. It eats sponges and the like and lives in the colder waters off the west coast of the US.

It also has an interesting feature common to many members of its family. It has a 'brood pouch'. The surface that you see is actually a soft covering which covers the true surface of the sea star. In other members of the family, females will release their eggs from their gonopores (like all other sea stars), but retain them under that covering until they develop into juvenile sea stars and crawl out. In this particular species, they do not brood their young, and instead send them shooting out of the osculum, an opening in the covering. The osculum is generally used for exchanging water from the water vascular system to the outside, and can be seen opening and closing even in individuals who are not spawning.