#coelenterates

Rafting snails (family Janthinidae) are a niche group of commonly purple-shelled molluscs, which have taken to the open ocean: they live suspended under rafts of bubbles, preying on coelenterates (jellyfish-like organisms). Snails hardly seem well-adapted to life in the plankton, however, as they typically exist as grazers on the sea floor, and possess no real swimming apparatus. The jump from sea bed to sea surface is a significant one; only recently has light been shed upon the way the group evolved, by C. Churchill and associates of the University of Michigan. Genetic analysis indicates a close relationship between the Janthinid snails and the Epitoniids, bottom-dwelling predators, but the apparent key to the matter is in the breeding strategies of the two groups. Both deposit their eggs in frothy masses of capsules, which can become buoyant on their own, and with the addition of mucous bubbles would make a fine raft; the photo below shows a pair of Janthinids, one with several rows of suspended egg capsules attached to its bubble float. Transitioning to the open ocean gave the snails access to an abundance of coelenterate prey, which few other predators can feed upon.

-TJT

259 Blue Coral

weight 21g/105cts & dimensions 28x20x20mm

Rudolf Leuckart - Scientist of the Day

Rudolf Leuckart, a German zoologist, was born Oct. 7, 1822. When only 26 years old, he published his important book, Über die Morphologie ... der wirbellosen Tiere (On the Form of Invertebrate Animals--doesn’t “wirbellosen” have a nicer ring to it than “invertebrate”?). Invertebrates had been slowly rising in importance since the humiliating day in 1735 when Linnaeus divided the entire invertebrate subkingdom into just two groups, roughly translatable as "Bugs" and "Worms. Lamarck around 1800 had recognized 10 different classes of invertebrates, but there was still a lot of confusion about things like barnacles and bryozoans and such. Leuckart's contribution was to recognize that the group that Cuvier had called "Radiata" included two rather different types of animals, and these Leuckart called “Coelenterates” (jellyfish-like creatures) and “Echinoderms” (starfish-like organisms). He thus first identified two groups that we still recognize as discrete phyla. We have Über die Morphologie in our collections (see third image above).

Leuckart also became interested in parasites--indeed he is often called the “father of parasitology”--and it was Leuckart who first worked out the life cycle of organisms such as Trichina spiralis, a nematode that causes trichinosis. He realized that humans get trichinosis by eating infected pork, and that infected pork is recognizable by the small cysts that Trichina forms in meat muscle while it waits for its future host to eat dinner. This discovery led to the establishment of the very first laws anywhere calling for meat inspections as an aid to public health. 

As an aid to teaching, Leuckart developed a number of large printed wall charts. The Library of the Marine Biological laboratory in Woods Hole, Mass., has a complete set of these charts, and they mounted an exhibition of the charts some years back, two of which are reproduced above. The exhibition is available online.

 For many people wishing to visit Peru, and in particular in view of Machu Picchu Travel, one of the motivations of the principal is a unique holiday experience. If you fit this description, you may want to consider a trek Lares. You may have heard of the Inca Trek, a walking trip that ends in Machu Picchu. This is certainly a good way to spend part of their vacation in Peru. However, some people feel that the path is becoming too crowded (and in fact, is likely to need to book your adventure to 6 months in advance if you plan to make the hike of the Inca). For an interesting alternative, check out one of several hiking trails that take you through the incredible scenic beauty and breathtaking scenery in the valley of Lares. If, like most international visitors to Peru, he expects to see Machu Picchu during his time there, a trek Lares is a unique way to reach the fascinating history of the Incas. A walk through the valley of Lares will allow you to experience some of the world rarely viewed by foreigners, and provide a spike in interest livelihoods of farmers who work these terraces in the mountains. You can see live color ponchos, the thatched houses of stone, and herds of alpacas and llamas. The remoteness of this place, will improve your ride as you snake your way through the majestic mountains and valleys to the incredible Machu Picchu. Many hikers have found the Inca Trail to be increasingly popular in recent years and result in more visitors are exploring alternatives such as the Lares Trek. Walks to and / or culminating in Lares are offered by several tour operators. These routes will take you through beautiful mountain scenery very similar to the Inca Trail, but eventually a train that takes you to Machu Picchu, instead of you walk to the summit. Different locations can be called a "Lares Trek." A few tend to be more common, however, and I will list below. Note that most of these routes require four days of walking, but the routes most intense and of long duration are also available. The "Weavers Way walk is so named because the visits and Patacancha Huacahuasi villages, known for the production of textiles. This starts at the hot springs of Lares, and is one of the easiest routes. The second Cuncani passes through and around the base of Nevado Pumahuanca. It's a hard journey, but you will be rewarded with breathtaking views of snowcapped mountains and mountain lakes. Another route starts at Quishuarani and ascends into the mountains before ending in Patacancha. Like option # 2, this route also offers breathtaking scenery. A couple of options are a little harder, and therefore most of the first three walks. The first of these leaves Huaran and ends in Lares, crossing several steep hills along the road. If you want to do this really hard, you can try to complete it in 4 days. For a more leisurely pace (although difficult), take a day. The last of these popular options that I would like to discuss in this article is often called the "Tour of Homes." This is a very difficult journey completed in six days, and winds from Huaran Yanahuara.