Saturday, December 27, 2008

Photohunter: Squeaky

This cute little fish is a grunt sculpin. It is not a good swimmer, and it generally moves by using its bright orange pectoral fins to hop across the sea floor. They are generally found in shallow waters (subtidally) and live in crevices. They only get a little over 8 cm (3 .25 in). It has been reported that these fish make little grunting noises when you remove it from water.

Some interesting behaviour has been observed in aquariums during spawing season. Like most fish, males are generally the ones to guard the eggs. What's different is how the eggs are laid and fertilized. Normally, males have to entice (or chase) the females into their chosen nest site to lay eggs, however with grunt sculpins the females chase the males into a cave where they are laying eggs, and won't let them out until they are finished.

Thursday, December 25, 2008

Life Photo Meme: Procreation

Kingdom: Animalia

Phylum: Annelida

Class: Polychaeta

Order: Aciculata

Family: Nereididae

This was a bit of a tough choice for me, as I have an oddly large assortment of animal mating pictures (although I always kick myself for not having the camera on me the day I saw barnacles mating). I decided to go with this 'morning after' picture, as I find this type of procreation to be very bizarre.

These are Nereis sp. worms. They normally live on the benthos, but when these particular worms get ready to mate, their bodies undergo a startling transformation. Their internal organs degenerate, and their body cavity fills with gametes. They develop stronger podia (paddle-like feet) for swimming and better sensory organs. Then, when the moon is right, they swim up into the water column. Males will find a female and swim in circles around her... then they both explode.

So above you can see chunks of worm, white strands of sperm, and reddish-yellow eggs (both of which are released from the body cavity by the explosion).

Saturday, December 20, 2008

Photohunter: Wide

Can't get much wider than this. This is a preserved megamouth shark. This shark is known only from 38 specimens captured, salvaged, or recorded world wide. Despite its very large mouth, the megamouth eats small planktonic animals, such as jellies and copepods. It follows its prey, swimming up through the water column during the night and descending as night falls.

Thursday, December 18, 2008

Life Photo Meme: Royal

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Felidae

The lion (Panthera leo) has long been know as the king of the jungle. It is the second largest cat, with males weighing in at 250 kg (550 lbs) and about 2 m (6 ft) in length. However, this is nothing compared to the ancient American lion, the largest lions ever to have existed at 300 kg (660 lbs) and 2.5 m (8 ft).

Most people know about the superb hunting skills that the lionesses practice, and that the males basically do nothing but defend their pride from other male lions. Lions are the only cat to have sexual dimorphism, as the males have a distinctive mane. Some relatively recent research had some interesting things to say about the mane, in terms of selection and possible purpose. They found that males with darker longer manes were more likely to win male competitions, and be successful at mating. So, males may be able to size up their competition by comparing manes. But, males with darker manes had more difficulties in hotter weather conditions, to the extreme that their sperm can be come deformed. Of course, there is the idea that having a handicap to over come means that you are very healthy, and would make a good mate (think peacock tails). The original study can be found here.

Monday, December 15, 2008

Life Photo Meme: Glassy

Kingdom: Animalia

Phylum: Cnidaria

Class: Hydrozoa

Order: Leptothecatae

Family: Aequoreidae

How can you not think of jellies, when given the word glassy? This a crystal jelly (Aequorea sp.), one of the clearest jellies I can think of. I think this jelly is pretty neat because it is the jelly that GFP (green fluorescent protein) was isolated from.

I also really dig the way these guys eat. The batch of tentacles in the center surrounds the mouth. Unlike other jellies, the mouth can open really, really wide so that it can swallow and eat other jellies that are up to half its size. I've never seen another jelly that could open its mouth this wide, or even open its mouth at all. And they look pretty neat all full of food, too.

Sunday, December 7, 2008

Whales with scale

Here are two whale skulls, with my spouse kindly standing in for scale...The first is a gray whale skull. The grays are doing their yearly migration down from Alaska to Baja, where the mothers will give birth to their calves.

The second is a fin whale skull. They are the second largest whale and second largest animal, after the blue whale.

Saturday, December 6, 2008

Photohunter: Breakfast

This is a picture of Kellet's whelk, Kelletia kelletii, snacking on some fish for breakfast. Kellet's whelks are one of the larger gastropods (snails) found on the California coast. They generally tend to scavenge on dead or dying animals, but have also been know to eat crabs and lobsters caught in traps. They use their long, prehensile proboscis to reach into the traps, or in this case holes on top of the plexiglass container, and use the radula at the tip to scrap off flesh or drill through shells.

Thursday, December 4, 2008

Life Photo Meme: Inverts

Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Teuthida
Family: Loliginidae

The above is a picture of market squid, Loligo opalescens, eggs. The eggs are laid in capsules by the female in clusters on the bottom of shallow sandy areas. Each egg capsule can hold about 300 eggs, and the female can lay 20-30 capsules in a breeding event. Eggs hatch in 3 to 5 weeks, depending on the water temperatures. The hatchlings, called paralarvae, are about 6mm (1/4 in) in length at hatching.

Here is a cropped part of the above picture, so you can better see the little squids developing in their eggs. They didn't have any pigment yet, and were about 4-6 days from hatching.