Nature Blog Network

Tuesday, October 13, 2009

Pick a Card, Any Card

Another of the Ocean Challenge in the Classroom projects has been fully funded! So...
Pick a card any card, leave your pick in a comment or as a tweet to @eclecticechoes. The card with the most choices (or in a tie a random choice among the tied) will be featured here tomorrow.

Friday, October 9, 2009

Nautilus Night - Cephalopod of Diamonds

Ok. I said for each of the Ocean in the Classroom projects fully funded I would put up a post about one invert from the deck of cards I have been working on, along with a sneak peak at a card. So, since the Making Waves, Oceans and Landforms got fully funded, and in honor of Nautilus Night I bring you the Cephalopod of Diamonds - The Chambered Nautilus.


Classification for the Chambered Nautilus

Kingdom
Animalia

Phylum
Mollusca

Class
Cephalopoda

Order
Nautilida

Family
Nautilidae

Genus
Nautilus

Species
N. belauensis

ResearchBlogging.orgSome interesting facts about the chambered nautilus (and other extant nautiloids):

The 6-7 (there is still debate on the status of one species) extant species of nautilus come from two genera, the 4-5 smooth nautilus'(genus Nautilus) and the 2 species of hairy nautilus (genus Allonautilus - literally "other nautilus").

They are the only remaining cephalopods that retain an external shell, which they use for defense and as a buoyancy control system. The shell, with buoyancy control, was a significant weapon evolutionarily, as it afforded the early cephalopods the protection of a thick shell yet the advanced buoyancy control unchained them from the sea floor as most of the periods marine arthropods were.

Modern nautilus are generally found on steep coral reef slopes at a depth of 200-400m during the day. They rise at night to feed near or at the surface, using the adjustable buoyancy of their gas filled shells to good effect during the vertical migration.

Unlike other cephalopods, the nautilus do not have a lensed eye. The nautilus eye is more like a pinhole camera, leading to the hypothesis that it uses olfaction to find it's prey (mostly shrimp and other crustaceans along with some small fish.)

Nautiloids also have upwards of 90 tentacles (compare with 8 arms of octopods and 8 arms an two tentacles of squid and cuttlefish.)

Last bit for this post is their lifespan and reproduction. Most cephalopods are short lived with overall lifespans of even the Giant Pacific Octopus being around 2-3 years. For most studied cephalopods natural death from old age occurs after mating, (and for females egg guarding), which is only done once (called semelparity). Nautilus can live in 15-20 years and mate year after year (iteroparity).

The nautilus are the ancient lineage of the cephalopods, descendants of and most like the orthocerids and other nautiloids that were a major predator of the seas in the Ordovician period. Modern nautiloids are the only cephalopods that retain their external shell and are often considered to be "living fossils" as they are very similar in appearance to the ammonites and nautiloids that emerged half a billion years ago in the Cambrian. However recent molecular studies are casting some doubt on the appropriateness of the "living fossil" moniker. Studies published in the past couple years have revealed that the 6-7 extant species of nautilus evolved much more recently, around 2 million years ago, in the seas around New Guinea. They then


Sinclair, B., Briskey, L., Aspden, W., & Pegg, G. (2006). Genetic diversity of isolated populations of Nautilus pompilius (Mollusca, Cephalopoda) in the Great Barrier Reef and Coral Sea Reviews in Fish Biology and Fisheries, 17 (2-3), 223-235 DOI: 10.1007/s11160-006-9030-x

Thursday, October 8, 2009

Ocean in the Classroom Challenge

Today's a big outreach day!

First up, an outreach project I that has been part of my life for the past year is finally coming to be. This afternoon I will finally see the professionally printed version of my deck of cards that will be used to help teach molluscan diversity. They are still prototypes so I can't show them here just yet. Hopefully soon I can highlight a few of the cards along with some discussion about the animals on them and the process of making them. I am looking forward to hearing from the COSEE particpants at Avery Point who will be getting a sneak peak at them today through Saturday.

On a much larger scale Dr. M and Kevin have gathered together many of the top ocean bloggers to support some serious K-12 education outreach: Ocean in the Classroom Challenge. I just looked through the challenge and there are seven great projects in there, including several that are aquatic invertebrate centered. Personally I love the Invertebrates in my Tank, Waders and Coral Flip Book projects because they touch close to home, so to speak.

I would take the website hostage like the DSN boys are doing, but that won't work so well here where it has been so quiet lately. However, maybe the opposite will work, for each project that gets fully funded I'll put up a post on recent research about one of animals featured in the card decks.

Thursday, September 3, 2009

Channeled Whelk with Egg Cases


Family friends bought us passes for Project Oceanology's Enviro Lab cruises at an auction this summer, and finally, as the summer draws to a close, we were able to take advantage of them. Project O is an outreach center that focuses on marine science and environmental awareness especially of the Long Island Sound ecosystem. Their Enviro Lab boats are equipped with a small sample trawl, water quality samplers and sediment samplers. I had been on the Enviro Lab boats with classes from the Marine Science undergraduate program at Avery Point (Project O is located on the Avery Point Campus).

For Johann and Tammy it was a new and exciting adventure. Johann's favorite part was examining the results of the benthic sample trawl. After seeing the Mystic Whaler (Which chanteyman extraordinaire Geoff Kaufman often sails aboard) he was inspired to sing a round of "Donkey Riding" as he reeled in the line from the trawl. The fun really started when he got to get really hands on with the samples helping quickly sort the haul and get all the animals into the large wet tanks. In the haul were a dozen Scup (Stenotomus chrysops), several Sea Robin (Prionotus carolinus), some Atlantic Moonfish juveniles (Selene setapinnis), what looked like a small striped bass (I didn't get to see it but that was the description), a feisty female little skate (Leucoraja erinacea) and a spotted hake (Urophycis regia).

While there was quite a number of vertebrates in the haul, there were far more inverts brought up. Among the inverts there were in excess of a hundred spider crabs (Libinia emarginata), two lobster (Homarus americanus,)(both female), two European Green Crabs (Carcinus maenas), one Jonah Crab (Cancer borealis), several broad-clawed hermit crabs (Pagurus pollicaris) and one male Horseshoe crab (Limulus polyphemus). Molluscs were well represented as well with many mud snails (Nassarius obsoletus) and slipper shells (Crepidula fornicata)as well as a half dozen loligo squid.

The real prize though was this female channeled whelk (Busycotypus canaliculatus formerly Busycon canaliculatus). Johann spotted her and pointed out the fact she was currently "laying" and egg case string. Soon after the animals were sorted into the tanks, the guide showed the whelk and explained the egg case string to the guests, then she carefully (more or less) dropped the whelk back into the sound.

The main reproductive time for the channeled whelks is the fall. Egg strings like the one this lady is laying will consist of 40-160 or more egg cases all joined by a tough leathery string. Each case may have as many as 100 eggs inside, though the average number of eggs per case is closer to 40. Not all the eggs in each case are fertilized though and the unfertilized eggs serve as food for the young whelks which emerge from the cases as miniature adults.

There is a small fishery for whelks here in the Long Island Sound, mostly sold in Italian markets as scungili. Unfortunately the most common bait used is chopped up horseshoe crab.

Friday, June 19, 2009

A Cool New Backyard Visitor!

One of the joys about moving, and there are but few, is discovering the new critters inhabiting your property! My wife found this Spinybacked Orbweaver hard at work in our yard yesterday.

Friday, June 12, 2009

Zoanthid Histology

I uploaded some histology of a new zoanthid for collaborators in Japan to look at. Flickr is a great tool for sharing images and now I've found a work-related use for it! I don't have anything labeled but the descriptions for each image tell you what it is. The blue globby things are forams. Zoanthids are known to incorporate sand and sediment into their body wall to make them more rigid. As you can see from some of the cross sections, the mesenteries have very weak musclature. The staining protocol I used is called Masson's trichrome. Red stains for acidic tissues, like muscle fibers, while blue stains for basic tissues, such as connective tissue.

Saturday, June 6, 2009

Wednesday, June 3, 2009

Wear your Invert

We made our annual pilgrimage to a shopping mall the other day to visit the Apple Store (Closed for renovations!) and the tea store. On our way out Tammy spied some cool earings hanging in a small shop. What caught her eye from outside the store was the blue heron Cloisonné earrings. Once inside though she fell for the Monarch Butterflies. Today when I got home she showed me the creators website bamboojewelry.com. Tammy was psyched that they had nudibranch pins and earrings!


Actually they have a nice collection of marine and terrestrial invertebrates.


A persfect gift for your invert lover (take that however you need to!) or for yourself. Of course if you insist on having relations with a porpoise, Bamboo has you covered there too. But seriously wouldn't you rather wear a nudi?

Tuesday, June 2, 2009

The Deepest Cuke


A WHOI summer student fellow, holding one of the deepest sea cucumbers ever found, recovered from the Mariana Trench. Stunning to think of this little echinoderm living 9,000-11,000m down with pressures of 16,000psi or more. Image copyright WHOI.

The deep exploration buzz online lately has justifiably been about the hopefully avoidable, premature retirement of the JSL manned subs – read up on the issue at Deep Sea News, then SIGN UP to try and save them – but there is another vehicle out there right now that deserves some praise: Nereus.

Out of Woods Hole, Nereus is an ROV designed from the ground up to go to the absolute depths of the oceans. On the 31st of May, it went all the way to the bottom of the Challenger Deep, the deepest spot in the oceans at 10,902m. Nereus is now the only currently operating vehicle to explore the Mariana Trench and only the third in history to have done so: the manned Trieste in 1960 and the ROV Kaiko in 1995-1998. Read more about the technological hurdles involved in designing and building Nereus, along with it's maiden voyage to the bottom of the seas. The very bottom.

Monday, June 1, 2009

Circus of the Spineless #39 Is Up!

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Bug Girl's Blog is the host of this months Circus of the Spineless! Marine inverts represent with bivalves, crayfish and jellies. Also plenty of insects and arachnids for your viewing pleasure as well. Enjoy some fine nature writing and photography!