Hectocotylus

Hectocotylus:

The arm that gets all the fun –

Come mating season

Most male cephalopods (octopus, squid, cuttlefish, nautilus) have an arm dedicated to reproduction called the hectocotylus. Essentially a tube of muscle, the arm passes sperm packets to the female during mating. The structure of the hectocotylus can be species specific, making it a handy tool in helping classify an organism. The arm was named when one was found detached from the male after mating and still left in the female, thus being confused for a parasitic worm. Sadly, cephalopds are generally short-lived and most die after mating.

Ode to Fieldwork

Engines on – Away!

Samples see beneath the waves.

Red right returns you. 

The school year is finally here and I lucked out with getting on (and accidentally in) the water on the first day of my Experimental Marine Bio class. We practiced sampling with a ponar grab to take up sediments from the floor and using a secchi disk to measure light penetration. Here’s wishing you a good semester and lots of learning and good science!

Clownfish

Nemo’s father wept,

When the cold deep claimed his wife

And he became mom.

Clownfish (Subfamily Amphiprioninae) were made famous by Pixar’s Finding Nemo, to the point were fans both young and old at pet shops and aquaria go crazy after spotting a “nemo” fish or one of his friends. One of the interesting aspects of clownfish biology is that they are protandrous hermaphrodites. All start off as males and then a few become female as required. For finding Nemo this means that following the mother’s untimely death during a barracuda attack, the remaining parent should have become a female. I for one would have like to see how such a plot twist would have been received by the target audience.

 

Isopod, giant

Giant isopod

Lumbers, looking for a meal.

Eats too much to walk

The giant isopods, Bathynomus giganteus, exemplify the phenomena of abyssal gigantism where organisms in the deep ocean are significantly larger than their shallow water or terrestrial counterparts. For the giant isopod this translates into a “pillbug” over 70 cm long. Like isopods on B. giganteus feed on the “waste” that accumulates on the seafloor, mostly in the form of animal carcasses. True to the form of deep sea organisms, these isopods are adapted to living off of irregular large meals. When the isopod finally finds a meal it can eat so much that it won’t be able to move for a while afterwards.

Giant Isopod. Courtesy Wikimedia commons

The epic

Hey everyone. I’m extremely excited with the great reception my blog has been getting. I’ve decided to try something new, a sort of epic poem about oceans and the world. It’s being written slowly and evolving steadily. If you want to check it out it’s under the page called “The Epic” https://panthalassarising.wordpress.com/the-epic/   If you have any ideas, comments, feedback, suggestions etc please email me or leave a comment on the page.

Thanks!

Elliott

Shark week – Part 4

Skin glows like the sky

Etmopterus perryi

Smallest of the sharks

Sharks are almost always viewed as giant vicious fish. However, most sharks don’t grow more than a few feet long and only a few species are particularly dangerous, at least to humans. The Dwarf Lanternshark, Etmopterus perryi, is thought to be the smallest shark known to science with maximum sizes of 21cm. Like many animals in the deep these sharks exhibit Bioluminescence where they can produce light in special patterns on their skin from tissue known as Photophores. A mother Lanternshark raises the young inside her body, but there is no placenta or any other connection between the mother and pup, a condition known as aplacental viviparity.

The Dwarf Lanternshark. Courtesy WIkimedia Commons

Shark Week – Part 3

Rough, biting shark skin

Proto-teeth bound up in flesh

Always squeaky-clean

Besides giving sharks a smooth ride through the water by increasing hydrodynamics, the tooth like denticle scales that cover shark skin have been revealed to have another purpose, one that could benefit humans. Sharks are notoriously clean animals. They don’t have growths of barnacles like the large whales or sea turtles and neither do they tend to carry microbial life. Researchers are looking at this as a promising source of biologically inspired technologies to keep pathogenic organisms from spreading. By mimicking the diamond like pattern the denticles form it is possible to create an antimicrobial  barrier that is thin enough to cover surfaces in hospitals, public places, etc. The big benefit comes from reduction of caustic chemical disinfectants and, hopefully, slowing the use of antibiotics that lead to so called, “super-bugs” such as MRSA. The material could theoretically  be used on ship hulls and other underwater surfaces to protect them from Biofouling organisms without using paints laced with harmful compounds.

Shark Week – Part 2

Rhincodon typus

Plankton chugging mammoth fish

Whose back maps the stars

The whale shark, Rhincodon typus is the largest of all fish in the ocean today at over 10 meters and 3o tonnes. The whale shark lives off of plankton, a panphyletic group of free-floating organisms, by using a comb-like structure modified from the gills to trap its tiny prey. Individual sharks can be identified from the patterning of white spots on its skin, a very useful trait  for tracking and monitoring individuals of a population. Whale shark researchers have borrowed software from the arsenal of astronomers to identify the spot patterns on the shark as if they were tracing patterns of stars in the night sky. Whale sharks are highly migratory as they search for places to feed and breed. Recently massive aggregations of whale sharks have been discovered, hopefully to yield more information that is desperately needed about the life of these magnificent animals.

Courtesy of Wikimedia Commons

Shark Week – part 1

This week I will be joining the SeaMonster blog in honoring sharks and working to build for them a legacy of respect and honor their importance to Panthalassa. http://theseamonster.net/2011/07/shark-week-on-seamonster/

 

Nostril, tooth and eye

Lorenzini Ampullae

Arsenal of sharks

Sharks are masters of perception in the deep. Their keen sense of smell is well known, many figures are available on how many drops of blood can be sensed in how many swimming pool equivalent bodies of water, as is their eyesight, particularly for a fish. I am always most fascinated however with the Ampullae of Lorenzini. This network of receptors on their skin, which concentrates on the head, is able to pick up on the weak electrical fields emitted by nerves and muscles as an animal swims through the water. Because seawater is salty it is able to transmit these electrical signals to the shark. It’s an interesting thing to ponder how this particular sense would feel like to experience. Imagine seeing the movement of an animal, not by sight or sound, but by sensing the very motion of its muscles and nerves.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Orca

The pod emerges

White-flecked chatter flanks a school

Death makes room for life

Orcas (Orcinus orca, a.k.a killer whales) are one of the most recognizable organisms in the sea. This is probably due to their success in the animal entertainment world since their intelligence makes them prime candidates as show animals. As with many whales, Orcas are highly social animals that travel and hunt in pods. Being mammals, they dedicate much more time to parental care then most other marine animals. The Orca is a sophisticated and deadly hunting machine. They are apex predators. Until the modern age of man there was nothing in the sea that could hunt down an orca. While this may create an image of savage animals that destroy “helpless” organisms it’s important to understand that top predators are enormously important to ecosystems.  Without them, organisms lower down in the food chain would proliferate and the subtle mechanics of energy transfer breaks down.