Although the world’s oceans cover approximately 70% of the Earth’s surface, most humans interact with only the narrow strip that runs up onto the land. This bit of real estate experiences terrestrial conditions on a once- or twice-daily basis. None of these abiotic factors, including drying air, the heat of the sun, and UV radiation,…
Category: Marine invertebrates
My favorite larva — the actinotroch!
Five days ago I collected the phoronid worms that I wrote about earlier this week, and today I’m really glad I did. I noticed when I first looked at them under the scope that several of them were brooding eggs among the tentacles of the lophophore. My attempts to photograph this phenomenon were not entirely…
A different take on ‘vermiform’
If I asked you to draw a worm and designate the front and back ends, you’d most likely come up with something that looks like this: And you would be entirely correct. A worm, or any creature described as ‘vermiform’ for that matter, has an elongated, wormlike body. Some worms have actual heads with eyes…
Lunacies
For several centuries now, Earth’s only natural satellite has been associated with odd or unusual behavior. Lunatics were people we would describe today as mentally ill, who behaved in ways that couldn’t be predicted and might be dangerous. The erratic behaviors were attributed to the vague condition of lunacy. These words are derived from the…
The fluidity of sex
We humans are accustomed to thinking of sexual function as being both fixed and segregated into bodies that we designate as either Female or Male. And while we, as a species, generally do things this way, in the larger animal kingdom sexual function doesn’t always follow these rules. Many animals are monoecious, or hermaphroditic, having…
Now you see it, now you don’t
This morning in the intertidal I was reminded of how often I encounter animals I wasn’t looking for and almost missed seeing at all. That got me thinking about color and pattern in the intertidal, and how they can be used either to be seen or to avoid being seen. Some critters–the nudibranchs immediately come…
Peanut worms!
If I ask my invertebrate zoology students to name three characteristics of the Phylum Annelida, they would dutifully include segmentation and chaetae (bristles) in the list. And they would be correct. Annelids, for the most part, are segmented and many of them have chaetae. But in biology there are many exceptions for every rule we teach,…
Eight is enough
One of the defining characteristics of the Phylum Mollusca is the possession of a shell, which serves both as a protective covering and an exoskeleton. We’ve all seen snails, and some people may have noticed that snails often withdraw entirely into their shells and even have a little door that they can use to seal up the…
Friends in strange places
Animal associations can be strange and fascinating things. We’re used to thinking about inter-specific relationships that are either demonstrably good or bad. Bees and flowering plants–good. Mosquitos on their vertebrate hosts–bad. In many cases the ‘goodness’ or ‘badness’ of these associations is pretty clear. However, there are cases of intimate relationships between animals of different…
Gastropods x3
This past Monday I did something rare for me: I returned to the same intertidal site I had visited the previous day. I enjoyed myself so much the first time that I wasn’t able to refuse an invitation to go out there again. The site, Pigeon Point, is one of my favorites, especially in all of its spring…