Biology Things: Get in The Water

  This month’s post is reminiscent of last month’s, more about toxins. However, let’s start with something different. The Ocean Sunfish, genus Mola , is odd-looking—it looks somewhat like a fish that has been cut in half. In addition, these species contain many superlatives. They are one of the largest bony fishes, reaching 3.3 meters and 2740 kg (6000 lbs). Females possess a remarkable reproductive capacity, producing more eggs than any known vertebrate, a staggering 300 million at a time. The little fish fry are tiny. The fry can grow up to 60 million times its original weight before reaching adult proportions, arguably the most extreme size growth of any vertebrate animal. In 2016, researchers sequenced the genome, discovering several genes that might explain its fast growth rate and large body size. Figure 1. Drawing of an adult  Ocean Sunfish, Mola mola . The Hoodwinker Sunfish, Mola tecta, is a species of Sunfish that has only recently come to light, discovered in 20...

  Public Service Announcement. The fun of living in an agricultural-dominated state: Toxic algae season has begun. Water sampling in my local area, Nebraska, began last week. I have blogged about similar things, but the problem is getting so bad that a revisit is warranted. This problem is lowering the quality of life for millions, killing fish, pets, and people, and will soon be killing humans at an alarming rate. Most harmful algae blooms in Nebraska are caused by blue-green algae/cyanobacteria, which produce toxins. The major toxins of concern are Microcystins. Recommendations issued by the U.S. Environmental Protection Agency (EPA) trigger a health alert at 8 parts per billion of the toxin microcystin. Read that again: 8 parts per 1,000,000,000. Dangerous stuff.  When a beach is under alert, it is recommended that no contact with the water occur. Microcystins are potent liver toxins and human carcinogens. They can also kill livestock and pets that drink affected...

The Lymnaaeidae family of freshwater snails are right-handed pond snails. Common in the water hole near you.  Early workers on freshwater snails distinguished three genera within the Lymnaeidae family: Lymnaea , described by Lamark in 1799; Galba , described by Schrank in 1803; and Stagnicola , described by Jefferys in 1830. A wee bit later, in 1885, the genus Fossaria was described by Westerlund; this is generally accepted to be a synonym of Galba . Hubendick reined things back a bit, putting them all in the same genus, Lymnaea , in his 1951 work, indicating that the differences were so minor that separate genera were unjustified.   Side Note: I’m ignoring more than a few genera, namely Radix , Bulimnea , Plurolinaea , and Acella . I’ll list even more later, so stay tuned.  And there it did not stay: Workers on snails have swapped back-and-forth using these genera, or not, over the years. It gets confusing as the first designations were separated primarily by the siz...

 Fish are great: Here is a phylogeny, an evolutionary history, of fishes.  Evolutionary groupings are the thing in biology. All animals in a named group, mammals, for example, have a common ancestor or should. A little bit ago (okay, a long time ago), analyses of the group that generally were called fish, including sharks, bony fishes, lungfishes, and more, were found not to have a single common ancestor. The same situation also applies to reptiles; there is no common ancestor, and it doesn’t fit a neat evolutionary grouping. It turns out that birds are grouped with dinosaurs—valid and worthy science. But what do we do with the term fish if fish do not exist? An unfortunate carryover is that fish is in the name of many things that are not fish but were once kinda fish, Lungfish, for example. This is a common problem in the English language: Silverfish and starfish are not even pretending to be fish. Do not get me started on seahorses. Side note: The wordsmiths tell me that I ...

Here, I wax on about Marine protected Areas (MPAs) and their importance in saving the oceans, the planet, and ourselves. I have waxed on about conservation issues in past blogs and will do so again. It’s important. This one is a little more of a ramble, associated with the state of my mind at the moment I suspect.                    Figure 1. Dark blue areas mark areas of the world ocean that are designated as protected areas. In the US, there are more than 1700 area designated Marine Protected Areas, which are marine regions with some level of protection. The largest is Papahanaumokuakea at 1,515,714 square km. The amount of area protected above may cause you to think that much of the ocean is protected. It is not. The addition of Papahanaumokuakea in 2006, and additions of other protected areas since, bring the percentage of the ocean under some kind of protected category to about 8% (some estimate lower, but I’ll try to be optimi...

Aristotle may have known about the teeth within the mouth of snails, but if so, his writings on it were limited. The radula is a toothed tongue or dental ribbon snails use to scrape algae off rocks or aid in drilling a hole in other mollusk shells to try to eat them. This structure is sometimes called the odontophore, but that term refers to the cartilaginous base, the structure on which the teeth sit. Though Aristotle might have observed this ribbon, it was officially discovered by Swammerdam in a work published after his 1680 death. By the mid-1700s, the ribbon was described in several species: rows and rows of tiny teeth pointing toward the stomach. The first drawing appears in a work by Poli in 1791.                  Figure 1. Radula Drawing. In Poli 1791.                                      Figure 2. Radula Drawing col...