Archive for November, 2008

November 30, 2008

Caught in the Seine: Permit

juvenile permit caught in the Indian River Lagoon

Adult permit are absolutely enormous fish.  Trachinotus falcatus routinely average twenty to twenty-five pounds but the record holder for Florida waters was 51 lbs 8 ounces!  Its incredible then, to me, that such substantial adults start life as such a diminutive size. 

When I first began teaching in the IRL system, these tiny reddish and silver fish with large red eyes and entirely transparent caudal fins were quite the mystery to me.  A fellow naturalist even took to naming them “butt fish” because we couldn’t easily see their tails.  These pico-sized permit are likely in the weeks-old category of life and measured no more than a centimeter. 

Incredibly, although the books disagree, we find juvenile permit like this one all along the IRL system at several stages of growth (1-4 cm usually) at several months during the year.  Its hard to believe that these puny babies grow up to be such titans.  Remarkably, if you can provide a home for the adults, permit are rather easy to maintain in lagoon aquariums.  A diet of flake and frozen mysis is eagerly accepted and growth can be very quick on a heavy diet. 

November 25, 2008

Caught in the Seine: Striped Blenny

Striped blenny

I thought I might take some time out every few field trips to start taking, logging, and posting photos of some of the juvenile fish and other creatures that inhabit Indian River Lagoon waters.  Since the lagoon is a nursery ground for several dozen fish species (perhaps hundreds in fact) there are many stages of life present in the estuary.  That can make it really hard to identify your catch in some cases.  I happen to love FishBase and also LarvalBase to assist me with identifications, but even those resources aren’t foolproof.  Sometimes you just have to get lucky (or become an expert) to figure out what you’ve caught. 

To start us off, I’ve chosen an adult fish.  Striped blennies are very common in the upper reachers of the lagoon both in Mosquito Lagoon, Banana River, and the main Indian River Lagoon tracts.  (All three waters feed into the overall IRL system.) 

Chasmodes bosquianus usually retreat to deeper water during winter, even in Florida, but are found along most of the coastline of the eastern United States in the summertime.  They’re frequently found on hard bottom, rock reefs, and oyster reefs in much of their range.  Within the IRL one of the best places to find these pugnacious little fish is to pull up abandoned shells of crown conch and tulip snails.  The blennies often make these discards their homes and will defend them – even against a giant human. 

Incidentally, striped blennies make great classroom aquaria fish.  They are alert and interactive fish with a hardy background and can be kept in a range of salinity conditions.  They seem to do best kept within 15 – 25 ppt salinity and feed happily upon a mixed diet of frozen mysids, carnivores flakes and pellets.  They are aggressive with cohorts, so be careful if you intend on mixing various sizes of striped blennies.

November 24, 2008

A Gentoo Takes Refuge

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I’m really not sure how I feel about the above video.  A) These people are wayyyyyy too close to wild killer whales!  Even if they’re not in US waters that fall underneath MMPA provisions they should be a little more sensible of their own safety. 

B) By becoming a gentoo refuge this film crew is interferring with wild behavior.  While there is a certain philosophy that no system can be observed without the observer changing that system, there is something to be said for being passive instead of active observers of wildlife.  Maybe that seems odd.  However, if you’re right in the middle of a hunt, or perhaps a hunting lesson for calves (some of the dorsal fins looked very small), you’re effectively interacting with wildlife and foregoing the ethic of respectful observation across a distance.

November 23, 2008

A Bias Towards the Cute and Fuzzy / The long lost relatives of baby manatees.. baby elephants!

Tiny manatee footprints caused me some alarm a few days ago, but something else that happened that day has been plaguing me all weekend.  Once I had explained to my students that it was unusual for a small manatee to be alone they immediately became concerned for his welfare.  While this is close to the sort of stewardship we want to inspire in our children and in our communities, the moment wasn’t entirely complete.  Why not?  Well.. there was a certain disconnect.

Earlier in the day the same students that became teary-eyed over the lonely state of this small manatee were throwing comb jellyfish at one another and holding fish so tightly in their hands that I was afraid they would squish the poor things.  While I certainly teach students proper handling its not always possible to teach them to respect those things which are often perceived to be lower than humans and other animals – especially mammals – with which we easily identify.  Communicating more respectful values and attitudes about such animals is a constant challenge for me.  Afterall, most of my students kill spiders they find in their house and yank the tails off of anoles

Lets face it, killifish aren’t exactly as cute as a manatee calf and simply don’t elicit the same sort of mammalian “warm and fuzzies” that probably derive out of some instinctual programming we carry to respond to infants with strongly protective behaviors and instincts.  Maybe its just a mammal thing, but I wish it were easier to transfer that kind of deep seated concern and compassion towards scaley and slimey vertebrates and invertebrates that deserve just as much attention and understanding.  Enigmatic species – which are often mammals – may make great ambassadors for habitats and whole ecosystems but when it comes down to it the nonmammalian niche holders need champions too. 


November 23, 2008

Manatees Pretend to Be Kraken

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Andy, a fellow naturalist, has a habit of jokingly calling manatees “attack beasts”.  At least I thought he was joking.  It seems Andy had a bit of a run in with some manatees a few months ago when they sidled up to his kayak and decided to investigate it.  I thought he was full of tall tales until I found the above video. 

Someone should tell these tiny cow-Krakens that they aren’t abiding by the Marine Mammal Protection Act and need to maintain a distance of 150ft! 

November 22, 2008

A Flash In A Bucket

(c) agentlebossanova / flickr 

I have bioluminescence on the brain.  I regularly conduct plankton tows within the Indian River Lagoon system that yield a scatting of amphipod larvae, veliger stages for snails, mysids, nauplii from any number of crustaceans, and copepods galore.  Right now there are plenty of comb jellyfish (which aren’t really jellyfish at all but belong to the ctenophore group) as well. 

I’m sure contained in these samples are plenty of bioluminescent phytoplankton. The IRL system regularly produces blooms of such plankton at certain points of the year and smacks of comb jellies are themselves bioluminescent.  Wherever they congregate, feeding on plankton, if disturbed they exhibit a brilliant flash of greenish blue cold light. 

Yesterday I brought home a bucket of lagoon water and left it in the kitchen for use in the morning.  During the night I got up to check on a noise and accidentally kicked the bucket and the disturbance caused a brilliant green flash inside the container.  I was so surprised that in my half awake state the unexpected brightness actually made me jump!  I continued to disturb the water and the flashes of light gradually faded like the ebbing of a battery on a flashlight. 

This, of course, makes me want to go out on a night kayak in the IRL to harass more plankton into emitting its own variation of natural cold fireworks. 

November 21, 2008

Live in the Dark? Make Your Own Light!

figure one from the PLOS One study

Heard of GFP?  Green fluorescent protein is one of a slew of fluorescent proteins (FPs) used in the field of molecular biology and biotechnology to visualize genetic expression patterns in model organisms and live cells.  The original GFP, like nearly all other FPs, was sourced from various marine invertebrates hailing out of shallow water habitats including corals and jellyfish. 

Interestingly, it looks like we might be able to get fluorescent proteins from ceriantharians (otherwise known as tube anemones) that live in the depths of the Gulf of Mexico, as crazy as that might sound.  Many deep sea residents are known to emit their own light – such as the counter illumination seen on some species in order to blend their bellies with the brightness of water layers above them when viewed from below.  A team of researchers recently published to PLOS One their findings of a new GFP-like protein that might prove useful in future live cell visualization studies.  This of course, makes me think of one of my favorite movies as a kid – The Abyss – where the “aliens” were similarly brilliant with bioluminescence. 

November 20, 2008

Heron Nests in November


This morning a gorgeous great blue heron flew just over head with a gigantic branch in its beak.  At first, this sight just didn’t register with any logic I had stored in my naturalist brain.  And then I remembered, in Florida, winter is nesting season for many birds. 

Florida has two major seasons: wet and dry.  Wintertime for the bulk of the United States is dry season in the sunshine state.  Less rain means lower waterlines in many of the river systems, ponds, lakes, and streams in the area.  And lower water means concentrated fish stocks.  So when is the best time to be a fish eating heron or stork in Florida?  Right now. 

Year after year a pair takes up residence in tall pines near us and makes use of the same nest each season.  I’m not sure if its the exact same female and male, or if they add significantly to their home with every nesting season, but it is fantastic to watch the ceremonial exchange and presentation of nesting material between partners.  I can’t wait to start the watch for hatchling herons. 

November 20, 2008

Banking Elkhorn Coral for the Future

(c) USGS: Caroline Rogers

Apparently a researcher with the University of Alberta is building a sperm bank for Elkhorn coral (Acropora palmata).  This past summer Dr. Acker, a frozen tissues expert, joined a group of coral researchers during an elkhorn spawning event and attempted to freeze eggs, sperm, and larvae.  They were successful with the sperm, but it doesn’t appear that they were able to preserve eggs or larvae. 

My only real concern with this sperm bank is that packets were apparently collected from just one area of a reef and from only “thirty to forty Elkhorn individuals”.  As recently discovered, the genetic toolbox for Acropora species might be mightier than we think.  It would be a good idea to bank more populations to ensure that long term genetic viability is likewise preserved.  I’m also curious to know how effective these frozen sperm are when, well, thawed and brought back to life.  In fact, maybe we would better serve our corals to simply learn more about their population genetics for conservation.

Would you be shocked to know that this sperm bank isn’t the only one of its kind for frozen wildlife tissue?  Well, don’t be!  The San Diego Zoo has had the Frozen Zoo project for ages hosted through their center for Conservation and Research on Endangered Species (CRES). 

November 19, 2008

Tiny Manatee Footprints

The lagoon was beautiful today: the wind was whipping, there were sparkling sunbeams glinting off the white caps, and the shallows were shockingly clear.  Oh, and the water felt like tiny knives sinking into your skin.  The thermometers may have read 65F but it felt all of 32F.  I felt like a naturalist popsicle.  

Temperature doesn’t just bother me, it sends warm water loving manatees towards refuges within the interior of the state at freshwater springs and in the outflow areas of power plants.  Yep, they’re like manatee saunas in winter.  In fact I had just finished explaining to my students that we were unlikely to see manatees when water temperatures drop below 68F that a relatively tiny set of footprints dotted the surface in a small cove near our site on the Banana River in Cocoa. 

Manatee footprints?  Sure.  Because of the downstroke of their paddle manatees create circular disruptions that look like glassy spots if they’re close enough to the surface.  And when a manatee is on the move these spots can indicate direction since the footprints enlarge as they slowly disappear.  Its not your classic v-shaped wake from a boat, but it’ll work. 

(c) USGS: Sirenia Project

I became concerned about halfway through my observations of this probable juvenile when I saw that he consistently approached the docks despite the noise from my students.  It also became clear that he seemed small to be on his own at ~4ft in length.  He did seem to be in great shape otherwise and was actively scouting the area, investigating the dock structures, and munching on – of all things – manatee grass.  The sighting became a fantastic teachable moment for the students about the Marine Mammal Protection Act, threats to manatees, their conservation, how to report ill and injured manatees, and the current population size.

Luckily enough an FWCC officer was in the area before I left the site so I was able to relay my observations for a heads up on this fellow’s status.  They’ll continue to keep notes on his sightings and, so long as he continues to behave normally, will let him find his way.