Wednesday, August 28, 2013

Zac - One last adventure blog

Giant Green Anemone - Anthopleura xanthogrammica
With a summer of research behind me now, I have had a little bit of free time to wander around the Oregon coastline and experience some of the scenery.  My fellow intern, Cris Rangel, and I immediately took advantage of this free time by renting an outfit of SCUBA gear and immersing ourselves in the murky Oregon waters. Visibility was limited to just a couple feet but fortunately, being biologists, we were perfectly happy to keep our noses pressed to the holdfasts analyzing the incredible invertebrate biodiversity on these rocky shores. We did our first dive at Simpsons Reef (which involved a good ten minute walk in full SCUBA gear) and our second dive at OIMB beach. 
Sea Lemon - Anisodoris nobilis

Both of these locations offered a number of targets for our borrowed underwater cameras (thank you Richard Emlet!) but the images above and to the left were surprisingly the only ones worth sharing from Simpsons Reef. As it turns out, it is quite difficult to work a small camera while wearing 7mm gloves and the surging current certainly didn't help. OIMB beach, seen below, was far more conducive to underwater photography. As you can see, this is a picture perfect entry point and I think that we enjoyed this dive the most purely due to ease of access. 

A great day for diving at OIMB beach, the kelp forest dead ahead is our target location.
Dungeness Crab - Metacarcinus magister
The dive off of OIMB beach features a sandy bottom peppered with numerous dungeness crabs. The image to the right is a picture of me holding an especially large dungeness. The male crab (see the telson in the image at right) was holding onto a presumed female crab in a characteristic pre-mating display. These crabs can only successfully be inseminated immediately after molting so a male will hold onto a female - sometimes for several days - until she molts, at which point he will inseminate her. Other notable marine invertebrates included a number of "Crawling Beauties" (Janolus fuscus) - a relatively common aeolid nudibranch (below left) - and what appeared to be the siphons of many  rock boring clams (Penitella penita).
Rock Boring Clam - Penitella penita
Crawling Beauty - Janolus fuscus
These clams feed by extending their paired siphons into the water current to feed.  Water is drawn into the shell where both oxygen and nutrient rich particles are extracted. The incurrent siphons of these clams are decorated with branched projections that distinguish them from the simple circular opening of the excurrent siphon.

One last view of the Oregon coastline
After our diving it was time for Cris and me to head back down the coast to Santa Barbara, but not without making some stops to admire some of the coastal wildlife. We did not have to drive long before a gang of elk along the side of the road attracted our attention.

Roosevelt Elk - Cervus canadensis roosevelti
The Roosevelk Elk is the largest remaining subspecies of elk. The adult bull seen left is absolutely enormous; the antlers alone were at least the size of my torso. This particular gang (herd) of elk had at least 20-30 cows and a handful of young males. Our next target location was The Avenue of the Giants - in Humboldt Redwoods State Park. A quick walk down from the side of the road led us to a little hidden paradise featuring a broad, meandering stream filled with underwater biting things - as Cris can attest to - and lined with old growth redwoods. Of course my attention was immediately drawn to the plethora of insects.

Cardinal Meadowhawk - Sympetrum illotum
The image above features a dragonfly while the image below features a damselfly. These are both basal insects winged insects (evolutionarily speaking) and are relatively closely related to one another.  Both adult forms share fairly similar ecological niches but can easily be distinguished from one another.  As a general rule of thumb (but certainly not always) dragonflies are larger and spend more time flying while damselflies tend to flit from perch to perch, spending much less time flying. The most distinctive difference, however, is the way that they hold their wings.  Neither insect are capable of folding their wings over the abdomen the way the neopterans ("modern" insects) do, but damselflies hold them up above the thorax while perched and dragonflies hold them down horizontally.
American Rubyspot - Hetaerina americana

The images above and below feature the exact same species of damselfly (and if I remember correctly, the exact same organism) and both pictures were taken with more or less the same camera settings.  The significant difference in coloration of the insect between these images is purely due to the angle of light. This structural coloration is due to wave interference and depends strongly on the angle of viewing in relation to the angle of light
American Rubyspot - Hetaerina americana
The "pseudopupil" seen in the dragonfly below is not a true pupil, but rather a collection of photoreceptors (ommatidia) that are all collecting the light that would otherwise bounce off of the dragonfly's compound eye and be absorbed by your own photoreceptors. Essentially the pseudopupil represents the cluster of ommatidia that are all aligned directly with your own optical axis, so, this pseudopupil will be present no matter what angle you look at the eye and it will always seem to be looking directly back at you... creepy.
Cardinal Meadowhawk - Sympetrum illotum
We also found a cool praying mantis at a gas station in the middle of nowhere... here is a picture (check out those pseudopupils!)

European Praying Mantis - Mantis religiosa
Okay, enough nerding out for now, on to the next blog!

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