The Urban Pantheist

Who's that in the hole in the mud of the salt marsh in Wellfleet Mass?


And who's that in the shallow pool at low tide?


Who's congregating in the muddy water by the hundred?


Why it's the Atlantic salt marsh fiddler crab! (Scientific name: Uca pugnax) These adorable little scavengers were very abundant when my dad and I went walking by the shore on our recent visit to Cape Cod. Sexual selection by the female crabs has driven the evolution of one oversized claw on the males.

When tidepooling, sometimes you encounter incredibly fast, nearly transparent animals. I would have told you these are impossible to catch and identify, so it's a good thing I hang out with other naturalists. A friend who goes by eumorpha-dream on tumblr caught these grass shrimp (also "ghost shrimp") and identified them as "likely Palaemonetes pugio." They hang out in salt marshes eating bits of organic material, and forming an important strand in the estuarine food web.

I accompanied Alexis at one of her pet-sitting visits. I was charmed by this fresh water shrimp.


Another tank hosted a bevy of fancy guppies.

Last weekend I went to the Cape to visit the seashore and hang out with friends. This is when I first got there and couldn't find anyone but I liked the random green things growing on the beach.
( Read more... )

It was surprisingly warm today, so I took Charlie to Ward's Pond, despite the rain.
A soda bottle sailboat sat on the still, leaf-choked pond.
( Many pictures )

Photos by cottonmanifesto. Location: Castle Island Beach (low tide).

Urban species #186: Northern acorn barnacle Semibalanus balanoides

Barnacles are a staple of life at the shore. On pilings, wharves, boat hulls and rocks, a white crust of shells accumulates. Most people pay them no mind--they certainly don't think of them as animals. Or if they do, they consider them to be some kind of lesser mollusk, notable only for the drag they place on the vessels on which they cling. In fact, barnacles are essentially shrimp, that glue their heads permanently to some object, surround themselves with armor, and spend their lives collecting plankton with their feet. When the tide is out, they shut the plates of their armor tight for hours, patiently waiting for submersion to return. This success of this strange way of life is obvious, when one thinks of how ubiquitous barnacles truly are.

The northern acorn barnacle is the most common barnacle throughout its highly urbanized range, which includes New England and Northern Europe. Like many species of barnacle, it is hermaphroditic. It accomplishes the awkward act of fertilizing its neighbors with the use of a penis many times longer than its own body length. Fertilization is internal, and (reminiscent of their relatives, the isopods) results in live birth. Their larvae are free-swimming planktonic animals that are potential prey for a myriad of other animals, including whales and even other barnacles. Adult barnacles are preyed upon by sea stars, predatory snails, and occasionally gulls.


These youngsters may not have much luck, attached to this fragment of a ginger ale bottle, tumbling in the surf.

Urban species #093: Wood louse Oniscus asellus

First, let's address the name problem. We can call these animals woodlice or sow bugs if they can't roll into a defensive ball. If they can roll into a defensive ball, we can call them pill bugs. We can call all of them terrestrial isopod crustaceans, or even oniscideans, if we want to be scientifically correct, but in the interest of simplicity, I'm leaving behind the following common names: roley-poley/roly-poly, potato bug, armadillo bug, slater, ball bug, chuggy pig, butcher boy, carpenter, woodbug, hardy back, doodle bug, and cheeselog. You may collect yours when we're done, and use it as you please.

There are over 3000 known species of them, but there are just a handful that are urban. Pictured is the "shiny European sow bug," identified by its relatively large size (reaching just under 2 cm) and glossy dark-gray surface, as well as a host of more difficult-to-see features. The other common species are the "rough woodlouse,"Porcellio scaber, the soft matte gray colored one that I saw so much when I turned over logs as a boy, and Armadillidium vulgare, the common pill bug, which I have never seen in New England, though I am often assured that it is here. These three species are likely to have been originally natives of Europe, but are naturalized practically everywhere, and don't seem to be bothering anybody in their new homes. Most people rarely encounter these secretive animals, unless they deliberately seek them out, or have an especially moist home.

As the only large group of fully terrestrial crustaceans (relatives of crabs and lobsters rather than insects or millipedes), they need to keep their bodies wet to some degree or another. Their breathing apparatus allows water to be easily lost from their bodies, so they tend to stay where it is always damp. They are nocturnal, and will move away from a light that is shined on them.They eat vegetation, detritus, and fungi, and are generally considered to be beneficial soil-producing decomposers, though some gardeners complain of woodlice eating their plants. Found indoors they are a symptom, not a problem: some wood in your house is probably rotting.

Woodlice are being studied as living indicators of certain pollutants. Heavy metal contamination can be detected and quantified by examining its effects on these creatures. In my research I haven't answered one question I've had for a long time: When my brother's yard is sprayed with pesticides to control black widow spiders, how come the woodlice survive?