Life Photo Meme: Honor an Invert

Phylum: Ctenophora

This is a nice picture of a ctenophore from Monterey Bay Aquarium. Ctenophores are often confused with jellies, as they look similar, and have only two cell layers + the mesoglea. However, ctenophores lack the special stinging cells which characterizes all members of the cnidarians (jellies, anemones, and the like). They do have special sticky cells called colloblasts, which they use for feeding. They are active predators, and can use either sticky tentacles or muscular lobes to capture their prey. the above ctenophore is a lobed variety, and catches its prey by closing those large lobes around it. You can see some of the copepods that it had for lunch in its gut.

The other way comb jellies are different from your average jelly is: the way in which this animal moves. The creature cast produced an excellent movie describing this unique (for a multi-cellular organism) mode of locomotion. If you watch, you should also be able to explain why the comb jelly in my picture has beautiful rainbow stripes...

CreatureCast - Comb Jelly Movement from Casey Dunn on Vimeo.

After the storm...

Because of the storms and high winds which have recently rocked our coast, we've had a number of things wash up on the beach. The most spectacular of which was this...


A Risso's dolphin. We don't know why this guy died, but we do know that he is very young. Risso's get to be 10-12 ft in length, and are born at about 4-5 ft. He may have been just too inexperienced to ride out the storm. We won't know the cause of death for sure until someone does a necropsy. Very little is known about this species, so this little guy will help advance our knowledge.

Life Photo Meme: Ancient

I have lots of photos of ancient organisms, but I had to go with this picture of fossilized hadrosaur skin. First off, considering how fossils are formed, I am always impressed by seeing fossils such as these, and I am sure other feel the same way. Secondly, they offer a glimpse of what these animals may have looked like alive. Now, scientist are able to use some of these amazing fossils, notably fossilized feathers and protofeathers, and an old technique to get an even better view of what these animals looked like.

Zhang and others have reported that they are able to tell what color the dinosaurs feathers were by taking a look into the preserved parts of the cell using a scanning electron microscope. Protein pigments present in modern-day feathers and fur have unique shapes based on color, and are fairly resistant to breaking down. When these scientists looked at ancient dino (and bird) feathers, they found the same pigment shapes. Now they can tell by looking for the pigment shapes what color the feather was. What's more, by looking at the distribution of those shapes they can see if it had stripes, spots, or mottling.

I am looking forward to the new and improved museum models showing the actual colors of these amazing dinos and birds!

Life Photo Meme: Hostile

Kingdom: Animalia

Phylum: Cnidaria

Class: Anthazoa

Order: Actiniaria

Family: Actiniidae

This is a starburst anemone (Anthopleura sola), which is common in intertidal areas along the west coast. Anemones, like jellies, have stinging cells which they use to capture food and defend themselves. If you've ever touched an anemone, you've felt the sting as a sticky sensation.

In addition to the normal tentacles used to capture food, some anemones have a second set of tentacles which they inflate in the presence of other anemones. These tentacles, called acrorhagi, have larger stinging cells... larger than those found in the feeding tentacles. They will use the acrorhagi to fight with the anemones encroaching on their area.

This is complicated be the fact that some anemones with acrorhage asexually reproduce by splitting down the center. The two new anemones will not fight with each other, but will fight with any anemone that is genetically different. The anemone pictured above is solitary, and will not have any cloned neighbors, as clones from this anemone generally move away quick.

If an anemone gets beat very badly and needs a hasty retreat, they can inflate the bottom part of their body with air, and float away.

Life Photo Meme: Frosted

Kingdom: Animalia

Phylum: Mollusca

Class: Gastropoda

Order: Nudibranchia

Family: Tethydidae

I guess all larval animals have a clear, frosted appearance, but I choose this particular larva because it's special to me. This is a veliger larva, a larval stage which is typical to the marine snails. In particular, this is a baby lion nudibranch, Melibe leonina. This larva hatched today, and I am trying to rear them to adulthood.

The fuzzy bits toward the bottom of the veliger is cilia, which helps it swim. The two round dots that look like eyes are actually statocysts, which help the larva figure out orientation (up and down). These guys have a thin shell in the veliger stage, which they lose when they metamorphose into juveniles.

Adult lion nudibranchs live in the kelp canopy, and eat small creatures that live on the kelp or float by. They use their big oral hood much in the same way a Venus fly trap catches flies. Because of the way they feed, they are one of the easiest sea slugs to keep in a public aquarium. They are also one of the few sea slugs to swim.

From Biological Tales from the Brine Queen

It will take a little over month before these little veligers metamorphose and settle into the adult form. It will be a welcome challenge to try and keep some of them alive for that long.