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Ocean Genome Legacy Newsletter
February 2013

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In This Issue
Valentine's Day Under the Sea
Sustainable Seafod Update
Coming Soon...
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This month love is in the air! ... and under the sea! Take a break and read some Valentine's Day-inspired stories about love in the deep, including fish that "pucker up" and the bizarre mating rituals of marine organisms.

And, as always, follow our expeditions and other news from the marine world on our Facebook and Twitter pages!

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Valentine's Day under the sea
Make war not love...

Kissing fish
Kissing gourami males show aggression
Kissing fish, or kissing gouramis, are large, tropical freshwater fish native to southeast Asia popular in the aquarium trade. These fish have unusual mouths and use their toothed lips to rasp algae from stones and other surfaces. This rasping action is also used by males to challenge each other for dominance, a ritual that looks like "kissing" to love-struck humans.

If you're a Valentine's Day cynic...

...then angler fish species, like those in the family Ceratiidae, are right up your alley!

Anglerfish male
Close-up of male anglerfish fused to the female's back.
(Photo: Dr. Theodore W. Pietsch, University of Washington)

Because these deep-sea dwellers are rare, it can be hard for them to find a mate.  So once a male angler fish finds a mate, he never wants to let her go. But his method of keeping the love alive may not seem all that romantic. Among angler fish, all sizable individuals are female and most have what appear to be parasites attached. It turns out that these "parasites" are actually tiny males! Male ceratioids live solely to find a mate using their extremely well-developed olfactory organs. Once he finds a female, the male bites into her skin and releases an enzyme that causes their blood vessels to fuse! The male body slowly atrophies, becoming not much more than a pair of gonads, which release sperm in response to female egg release. This extreme sexual dimorphism ensures that, when the female is ready to spawn, her mate is always there. Too bad she can't count on him for much else. 


Underwater conga line...

Sea hares are hermaphrodites. In other words, they are equipped with both male and female reproductive parts.  These animals are virtually blind, and must rely on chemical communication via pheromones to find each other and mate.  They live alone most of the time, but when it is time to mate, watch out! During the mating season they congregate in massive orgies, forming "mating chains" of multiple individuals. In these chains, the gastropod at the front plays the role of female, the one at the end male, and all the others in-between play both roles. In this way the sea hares can both receive sperm and pass their own to a third party. These guys are truly the swingers of the deep!

Watch the video  



Giving it all up for love... 

Paper nautilus
The Argonauts, or paper nautilus, are a group of octopi like no other. After mating with a male, who is around 8 times smaller, a female secretes her shell, lays her eggs within the structure, and climbs in herself. Joining her inside is the male sex organ, or hectocotylus, that has snapped off and been abandoned during mating - OUCH! Not to worry, though. Males regrow a new hectocotylus every year.

Queen for a day?  

Clownfish reproductive roles change over time- the largest fish is the female
(Photo: J.E.Randall via FishBase)

Many fish species, such as clownfish, wrasses, and moray eels change gender (including reproductive functions),  during their lifetime. This is a normal anatomical process called sequential hermaphroditism. The best known examples are clownfish species (think "Finding Nemo") with a social hierarchy based entirely on body size. The largest fish in a group is female. When she dies, the most dominant male in the group changes sex and takes her place.


So if you think love is confusing for people, just think of our fishy friends and take heart. It could be a lot worse!




Click here to explore even more bizarre mating rituals! 


Update on Sustainable Seafood


Recently the US Department of Commerce declared New England ground-fishing a national disaster. With more and stricter fishing restrictions imposed for 2013, the Maine Congressional delegation has recently written to President Obama to ask for help for fishermen. The delegation asked for federal support to cover the costs of fisheries monitoring that in the past the beleaguered fishermen have been asked to bear.  Read here for more details about what the delegation is requesting. 


Green labeling or greenwashing? Increasingly, sustainable seafood labeling is coming under scrutiny. Can you believe the sustainable seafood labels in your grocers freezer? Learn more about this controversial topic from this investigative series aired on NPR.
 Coming Soon...

genetics vs genomics  

Conservation genomics      

The likely future of conservation genetics, conservation genomics is a rapidly emerging new field in conservation combining current conservation genetics with environmental ecology and recent advances in next generation sequencing, whole genome scans and gene-expression pattern analysis.  Together, they paint a more complete picture of ecosystems from populations to individuals, what changes cause them to thrive or fail, and what may be done to help with survival. 

We'll walk through these topics and more to explore this exciting new field!


Want to help OGL document and preserve the spectacular genetic diversity of our world's oceans?  Visit


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Dan Distel
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