All posts by Amanda

Sex life of Deep-Sea Creatures Always a Surprise

Posted by Amanda Rosenberger:     Check out this recent article from the BBC regarding promiscuous and bisexual behavior of a deep-sea squid, Octopoteuthis deletron.   Apparently males will exchange their ‘sperm packets’ with any other squid individual they come across, regardless of sex.   Researchers suggest that this is a strategy for males to make sure that they never miss a mating opportunity in a system where meeting a conspecific is a rare occurrence.   I wonder if that conclusion is simply based on the assumptions we talked about yesterday – that all species should have an ecology that maximizes fitness.   I wonder if it simply not a costly enough behavior in terms of fitness to be selected against; therefore, it continues.   An assumption that everything a creature does is somehow adaptive is actually a bit counter-intuitive to me.   What do you think?

https://www.bbc.co.uk/news/science-environment-14986769

A female deep-sea squid

 

Can CITES Help Shark Populations?

Posted by Matt Robinson:

I thought this video was interesting because it relates to the finning we’ve been discussing in class. Matt Rand, director of the Global Shark Conservation Pew Environmental Group wants to see hammerhead sharks  listed at CITES (Convention of the International Trade of Endangered Species) “the olympics of protecting endangered species”. Even though the sharks are listed as endangered, they are still in threat of going extinct because of the overfishing for their fins. CITES would make it illegal to trade hammerheads. By doing this they are hoping to take away the worth of the shark because people aren’t able to sell it so they stop fishing them all together. CITES is responsible for making elephant ivory illegal for trade. The regulations would be enforced at the trading ports, not on the open ocean. Let’s hope that CITES can save the sharks!

Memory like a goldfish

Posted by Sheena McAffe:   The old belief that fish have a three second memory is extremely untrue. Scientists have discovered fish actually have quite a good memory and in fact can actually be quite smart. They have also been noted of being capable of working in teams. A particular scientist named Dr. Kevin Warburton has been studying this topic for quite a few years. Dr. Warburton expounded, “’Fish are quite sophisticated. Fish can remember prey types for months. They can learn to avoid predators after being attacked once and they retain this memory for several months. And carp that have been caught by fishers avoid hooks for at least a year. That fish have only a three second memory is just rubbish.’ He has also said that the fish seem to exhibit human behavior in some instances. “Some behavioral traits that we think are very human, such as deception, fish have as well,’ Dr. Warburton explains, “Fish can recognize other individuals and modify their own behavior after observing interactions between other individuals. For example Siamese fighting fish will attack other members of the same species more aggressively if they’ve seen them lose contests with other fighters.’This just goes to show you, that fish not only are not as affable as we once thought them to be, but actually have an intricate social structure, advanced forms of communication, and can literally swim circles around their prey. This we need to re-evaluate our entire conception of these creatures.

BRISTOL BAY RED KING CRAB FISHERY OPENS OCTOBER 15: TOTAL ALLOWABLE CATCH ANNOUNCED

Posted by Angela Styczynski:   The Alaska Department of Fish and Game and the National Marine Fisheries Service have completed analysis of NMFS trawl survey data for Bristol Bay red king crab.   The 2010/2011 total allowable catch (TAC) is 14,839 million pounds. 13,355,100 pounds are delegated to IFQ (Individual Fishing Quota) while 1,483,900 pounds are appointed to CDQ (Community Development Quota). The 2010/2011 season will open at 12:00 noon on October 15 and remain open through January 15, 2011. There is no pot limit or buoy tag requirement for the 2010/2011 season and each vessel can carry up to 10 cod pots on board the vessel.   (https://www.fakr.noaa.gov/sustainablefisheries/crab/rat/adfg/093009bbrkc.pdf)

Taming the Wild Tuna

Posted by Tom Foster:   September 4, 2010, NY Times.

Aquaculture scientists have just announced that they have made a step towards converting the Atlantic Bluefin Tuna to a farmed species. With its huge metabolism this poses some issues. Looking at the other farmed fish of the sea, there are problems already at hand. The farmed Atlantic salmon   are causing problems for the native run fish that originally lived in the waters used to culture them. They have also been posted by some as fish not to be eaten because of some harmful chemicals that are accompanied by fish farming. Cultivating these Tuna could arguably be worse for the ocean and humans than farming the salmon has been. Instead of fish meal which is fed to the salmon, Tuna are predatory fish that need forage to survive. It has been found that 5 to 15 pounds of forage fish such as herring and sardines are needed to produce 1 pound of Tuna. At this rate the effects of farming Bluefin could be catastrophic to forage populations. We are running out of these enormous fish. Is the answer to farm them or leave the species alone to possibly be harvested to extinction?

https://www.nytimes.com/2010/09/05/weekinreview/05greenberg.html?_r=1&ref=fish_and_other_marine_life



An octopus mimic?

Posted: 27 August 2010 by BBC news:   A unique octopus adaptation has been discovered – impersonating a deadly fish to scare off predators.   By turning a mottled color and swimming in an undulating fashion, the octopus very closely resembles a local species of toxic flatfish.   Similar to mimics of the coral snake, monarch butterfly, and wasp, this species “co-opts” the defenses of another species without actually having having to incur the cost of the defense.   I am always amazed at the complexity and beauty of octopus behavior.   This is no exception!     To see the original article and a very cool video, click the link below:

Talented octopus dupes predators by impersonating fish

Photo courtesy of the BBC