5/20/12

Something new in Ancient Fishes

Visitors to the Aquarium may have noticed the new Ancient Fishes tank in the Thinking Gallery. It’s a pretty impressive tank and it’s nice to have some of our old residents back after this recent upgrade.



In addition to returning friends like the freshwater rays and the gars, there are also a few new species on display. Some of the most charismatic of the newbies are the two species of elephantnose fish (also known simply as “elephantfish”). Have you seen them!?

Elephantnose Overview
Elephantnose fish are in the order Osteoglossiformes, the sub-order Notopteroidei and the family Mormyridae. There are an estimated 200 species in this family ranging in sizes from 5 cm to 1.5 m. While not all species have the characteristic trunk-like appendage, they all have the ability to generate a weak electric field to help navigate their turbid environments.

We have two separate species in the Ancient Fishes Exhibit here at the Aquarium. The vast majority of the large school are known as Peter’s elephantnose (Gnathonemus petersii) and there is one specimen of the longfinned elephantnose (Brienomyrus longianalis).

Peter’s Elephantnose (Gnathonemus petersii)

Photo: Jacque Moreau via fishbase

Habitat: Rivers of west and central Africa - prefers muddy, slow moving rivers with cover
Size: Averages 23-25 cm in length
Diet: Insects and worms
Life-span: Estimated at 6-10 years
Peter’s elephantnose have the elephant trunk-like protrusion. While their name implies it is their nose, it is actually an appendage attached to their lower jaw. This sensitive apparatus is known to be used in communication, self defense, navigation and for locating prey.

Longfinned Elephantnose (Brienomyrus longianalis)

Photo: RMCA via fishbase

Habitat: Similar to that of Peter’s elephantnose
Size: Approximately 16 cm max length
*There is far less known about this species
Unlike Gnathonemus p., the longfinned elephantnose does not contain the trunk-like appendage implied by their name. In addition, while the Peter’s elephantnose’s anal and dorsal fins are equal in length, the longfinned elephantnose gets its name from the anal fin, which is much longer than its dorsal fin.

Elephantnose and the Electric Eel – A Story of Convergence
What do elephantnose fish and electric eels have in common? No, not just that their names are both fairly misleading, they also both emit electrical fields to sense their environment and locate prey. This is a fascinating example of convergent evolution – two unrelated animals developing similar adaptations over time.

The elephantnose fish have a brain to body size ratio similar to that of humans! Much scientific research has been dedicated to study how elephantfish use weak electric fields to sense their surroundings and possibly to communicate. Perhaps their cerebellum is so enlarged to help them interpret bio-electrical signals. [We recently posted about a new exhibit that shows how whales and dolphins communicate and navigate their surroundings! Check it out.]

While these species of elephantnose are themselves species of least concern, they share their freshwater habitats with other species in need of our protection. River habitats in Africa face many of the same issues as rivers all over the world (pollution, damming, overfishing, etc) so these fish can be used to inspire each of us to think about how our local actions impact global ecology.

5/18/12

Video: Goosefish Egg Veil

As promised in Wednesday's post, we wanted to share a short video of the egg veil on exhibit in the Northern Waters gallery. Sit back and enjoy.



The veil will likely start to disintegrate sometime this weekend, which is when the aquarists will likely remove it from the exhibit. So while you still can, get a first hand look at this very special event that comes only once a year. Learn more and see pictures from previous egg veils here and here.



5/16/12

Egg veil: It's that time of year again

As she has for the past couple years, our beautiful goosefish has laid another gossamer egg veil. Like last year, this one is about 60 feet long, made up of hundreds of thousands of tiny eggs held together in a flexible sheet.



Look for the goosefish, an anglerfish, in the lower left of the picture.



There she is. She laid the eggs over the weekend.



Without a male goosefish in the exhibit, the eggs are not fertilized. The veil will gracefully flow throughout the exhibit until this weekend. That's when the aquarist who takes care of this fish will likely remove the eggs, which is when the veil usually starts to disintegrate.

Come visit sometime this week to be sure to see this special sight! You'll find the goosefish in the Northern Waters Gallery, not far from the octopus. Be sure to tune in right here tomorrow, we're posting a video of the egg veil.

5/10/12

New Exhibit: Try to sing like a whale!

The Aquarium is always updating and enriching our exhibit spaces. It's exciting to put a new sea jelly on exhibit, or include new information about marine animals in a colorful display.

This is why we're thrilled to tell you about our newest touch-station called Voices in the Sea! You can watch the videos from this exhibit here.

You'll find these new panels and touch screen on the second level of the Aquarium, right across from the Schooling Exhibit. Just pause for a moment to check out the new panels on the wall. You'll learn some interesting tidbits about how marine animals—from singing humpback whale to whistling dolphins—communicate underwater. There's also information about Aquarium research on right whale stress from underwater noise pollution.




Now for the really fun stuff! Do you think you have what it takes to "whoop" it up like a marine animal? A wide touch screen lets you navigate to your favorite cetacean (whales and dolphins) and listen to their distinct calls. Then just tap the screen to record your own call and see how they compare! It's harder than you think.



We are grateful to the Pacific Life Foundation for making this exhibit possible. It was developed by the Scripps Institution of Oceanography with the Aquarium of the Pacific and even includes some of the Aquarium's very own right whale researchers!

Come check out our newest activity and learn about marine animal communication.

Another Calico Lobster Makes News

5/10/12 Update: The Aquarium has once again made news by holding a calico lobster that is bound for Biomes Marine Biology Center in Rhode Island. Here's a photo of the new lobster, and more information about lobster colors from Sam's previous post below.


Original 1/14/12 post:
Let’s get something out of the way: invertebrates are awesome! One of the coolest inverts around (in my humble opinion) is the lobster. There are so many cool facts you may not know about these animals, one in particular is that they come in a wide variety of colors!



This blue lobster can be spotted in the Aquarium's Gulf of Maine exhibit.


When most people picture a lobster they imagine a bright red animal on their dinner plate. However, lobsters are only red after they are cooked. Normally they have a brown/green/blue coloration. The really interesting thing about lobster color is all the possible color variations!


American lobster (photo: NOAA via Wikimedia Commons)


You can get blue lobsters (like the one pictured above), yellow lobsters, half brown/half orange lobsters, white lobsters…the list goes on. All of these different colors come with their own probabilities. While white appears to be the most rare at an estimated 1 in 100 million, coming in second place with and approximate 1 in 30 million is the calico lobster. I’m very happy to announce we’ve recently receive a stunningly beautiful calico lobster from our friends at Chatham Fish and Lobster Co.


New addition: A calico colored lobster! (Photo: Adam Clem)

When lobstermen in the area find these rare color variants in their traps they know how rare and special that is and they often donate them to the Aquarium. That is why here at the aquarium you can see a number of blue lobsters, even though in the wild they only occur at an estimated rate of 1 in 2 to 5 million.

In addition to these naturally colorful lobster residents, there is a lobster laboratory at the Aquarium that hatches and grows lobsters for research purposes that can artificially change a lobster’s colors. Our scientists figured out that all lobster color is derived from a pigment called “astaxanthin” found naturally in a lobster’s diet (the same pigment that turns flamingos pink) and by altering the amount of astaxanthin in a lobster’s food they can change their coloration. In fact, we recently added a new lobster to the Edge of Sea Tidepool Touchtank that was reared in the lab upstairs and is artificially blue.


(Photo: Adam Clem)

At this time, we’re undecided if this new calico lobster will be put on exhibit or used in our Live Animal Presentations (see our blog here about lobster presentations). But, next time you’re in the galleries keep an eye out for our impressively colored lobsters. Also, don’t forget…invertebrates are AWESOME!
-Sam