#bivalves

Get ready, get set, filter! Oysters are masters of removing algae, detritus, and plankton from the water, and none do it faster than the Hong Kong oyster. Despite reaching only 20 cm (7.8 in) in length, each individual is capable of filtering up to 30 L (7.9 gal) of water every hour!

There is a certain type of person who argues that we should just let invasive species be, either because they're already there and it's our fault in the first place, or because they mistakenly think that "naturalized" (being able to successfully reproduce in a place) means "part of the natural environment now". This is to say nothing of well-meaning folks who hate the idea of any animal being killed, even if it's to save an ecosystem.

Yes, it is true that our species is by and large responsible for the spread of invasive species, whether it is common starlings being intentionally released in New York City's Central Park in the 1890s, or barred owls hopscotching across the former ecological barrier of the Great Plains due to settlers planting trees and stopping tree-killing wildfires. But that doesn't stop the fact that these introduced species are doing damage in their new homes.

The quagga mussel, and its cousin the zebra mussel, both originate in Ukraine (the zebra mussel is also found in Russia.) However, they have found their way to waters around the world and, lacking their natural predators and competitors, have exploded in population to the point where they not only devastate the natural environment but human infrastructure as well.

There aren't any simple answers in eradicating any invasive species; even successful eradication campaigns have involved an incredible amount of time, money, and effort, to say nothing of education. I used to lived near Willapa Bay in extreme southwest Washington, which for a time was completely lined with invasive Atlantic cordgrass. This destroyed native wetland ecosystems and threatened oyster farms, so a concerted effort began among both public and private entities to rid the bay of this problem. It took years of consistently spraying the cordgrass with herbicides to knock it back enough to allow native plants to recuperate.

However, one landowner along the bay refused for years to allow anyone to spray the cordgrass on their property, believing that any herbicide use was bad and wrong and evil. Their protected patch continued to send seeds out into the rest of the bay, which would result in new populations setting up shop. It wasn't until a few years ago that the landowners finally relented, but their refusal demonstrated that even the smallest amount of cordgrass allowed to survive could quickly cause the bay to become overrun again.

why? why is malleus malleus shaped like that?? she looks like cow tools! or like a weird piece of driftwood. or a bipalium. a little bit like a hammer too. maybe that's why they call her the hammer oyster? probably not. she looks more like a prounch than any hammer I've seen before

glorpiness rating: coe tools

photographed by uwkwaj (CC BY-NC 4.0)

Today's animal of the day is the Alabama Lamp Naiad (Lampsilis virescens)!

Photo credit: earth.com

Also known as the Alabama lamp pearly mussel or the Alabama lampmussel, this species of freshwater bivalve is found only in the Paint Rock River Drainage of northeastern Alabama. This 58.7-mile-long tributary of the Tennessee River is actually home to several endangered species of mussels, fish, and other aquatic organisms, many of which are also found only in this region. The relatively small range of the species endemic to this tributary puts them at risk of extinction due to habitat loss or pollution, since it would only take a small portion of this region being destroyed to cause the downfall of this fragile ecosystem. Thankfully, much of the land surrounding the Paint River Drainage has been made into wildlife sanctuaries, which helps to preserve the Alabama lamp naiad and many other unique species.

Photo credit: U.S. Fish and Wildlife Service

These mussels only grow to around 2 inches long and have smooth shells that can range in color from a tan straw-color to greenish. The "naiad" part of their name comes from the nymphs of the same name from Greek mythology, who were considered guardians and human embodiments of freshwater bodies of water. Like the naiads of mythology, Alabama lamp naiads also help guard the water, in their own way. Mussels are bottom-dwelling filter feeders and can help filter out excess algae, fish droppings, and other organic materials from the water. An overabundance of these things can cause the water quality to decrease, which can lead to harmful algae blooms that drain the oxygen from the water and result in a mass die-off of fish and other larger aquatic creatures.

Photo credit: U.S. Fish and Wildlife Service

Some representative marine bivalves.