{"id":13766,"date":"2023-06-07T11:51:07","date_gmt":"2023-06-07T16:51:07","guid":{"rendered":"https:\/\/uwm.edu\/field-station\/?p=13766"},"modified":"2023-06-07T11:51:10","modified_gmt":"2023-06-07T16:51:10","slug":"closed-for-june-i-scuds-encore","status":"publish","type":"post","link":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/closed-for-june-i-scuds-encore\/","title":{"rendered":"Closed for June I \u2013 Scuds, encore"},"content":{"rendered":"\n
Salutations, BugFans,<\/p>\n\n\n\n
The BugLady usually closes for the month of June so that she can hit the trails, find newly-minted insects (preferably ones that she hasn\u2019t written about yet), and start building up a stash of pictures for future episodes – by spring, her picture files are dominated by unidentified insects. Also, having hit 700 episodes at the end of March, the BugLady feels the need for a victory lap\/vacation. Never fear \u2013 there will be something buggy in your mailbox every Tuesday in June.<\/p>\n\n\n\n
We\u2019ve spent the last five weeks celebrating American Wetlands Month, but really, every day is Wetlands Day, so here\u2019s an encore episode from 2011 that was in the queue when we ran out of Tuesdays in May. New words; new pictures.<\/p>\n\n\n\n
SCUDS<\/p>\n\n\n\n
Sit down and put your feet up, it\u2019s a long story.<\/p>\n\n\n\n
OK, the BugLady could (and will) regale you with all sorts of arcane facts about scuds (aka amphipods or sideswimmers), but the main \u201ctake-home\u201d here is that scuds are a hoot! And they\u2019re pretty cute, too. What impresses people about scuds is their locomotion – they zip around in your collecting basin, pausing under the shelter of vegetation, and then they\u2019re off again. In The New Field Book of Freshwater Life, Elsie B. Klots says that they walk and crawl, \u201cskittering\u2019 on their sides by flexing and extending their entire body, and frequently rolling up on their sides or back.\u201d Anne Haven Morgan, in her Field Book of Ponds and Streams, adds that \u201cAmphipods are accomplished water acrobats and can climb, jump, swim or glide with equal ease<\/em>.\u201d<\/p>\n\n\n\n Their pedigree: Scuds aren\u2019t insect \u201cbugs\u201d, but they are located under the giant umbrella of the phylum Arthropoda, along with insects, crayfish, scorpions, spiders, sowbugs, centipedes, fairy shrimp, and more. Arthropods (\u201cjointed legs\u201d<\/em>) are a mighty bunch that includes more than three-quarters of all animal species! Within the arthropods, scuds are in the subphylum Crustacea, class Malacostraca, and the order Amphipoda. That\u2019s a bunch of big names for a small critter, and it doesn\u2019t stop there – common names for this often indistinguishable bunch include freshwater shrimp, scud, sideswimmer, and gammarid (Amphipoda includes a large family, Gammaridae). The taxonomy of these critters is, of course, under review.<\/p>\n\n\n\n Most Amphipods are Marine, but there are about 150 species of freshwater scuds in North America. They are secretive bottom-dwellers, gracing cool, well-oxygenated springs and pools that have some calcium in the water for their shells (one source linked the size of scuds to the availability of oxygen in the water). They prefer waters that are \u201cfish-lite,\u201d and they may grace these waters in huge numbers, up to 10,000 per square meter. Look for scuds in tangled vegetation or under decaying leaves. Through these thickets, they crawl and pull themselves along, using clawed legs and bodily contortions.<\/p>\n\n\n\n Some species of amphipods are highly specialized, living in hot springs, caves, marine estuaries, or in deep, underground springs, and others are able to survive the drying of ephemeral ponds by burrowing into the mud. The presence of some kinds of amphipods testifies to a waterway\u2019s purity, but many species of scuds are tolerant of varying degrees of pollution. They can\u2019t live in poorly-oxygenated waters, and some species have fairly limited temperature \u201cwindows.\u201d<\/p>\n\n\n\n The BugLady read of behemoth scuds that grow as large as an inch, but most are barely half of that. Like a flea, a scud\u2019s body is ultra-streamlined – arched and laterally flattened (if you look at them head-on, they\u2019re pretty slim). The front end (cephalothorax) consists of the head and the first segment of the thorax and is home to eyes, antennae, and mouth. That\u2019s followed by seven segments of thorax, with each segment bearing a pair of long climbing\/walking legs (the first two pairs end in claws that are used in feeding and mating). Gills are located at the base of the thoracic legs. The last six segments are the abdomen, with six pairs of shorter appendages\/legs that aid in locomotion and also push oxygenated water toward the gills (Amphipoda means \u201cboth kinds of foot\u201d<\/em>). Scuds come in a variety of mostly neutral to pastel colors (influenced by their diet) and are often translucent. Telling one genus from another may require a microscope.<\/p>\n\n\n\n
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