Saturday, December 1, 2012

What's new?


The VLM is scheduled to re-open the downstairs gallery in about a week after several long months of flood recovery. In the meantime, the aquarium staff has been getting all our exhibits back in shape for public viewing. As of the scheduled date, we will have only one exhibit not ready for prime time - cavefish. The aesthetic rock work was completed yesterday, but its not enough time to cure the concrete work and cycle the tank...but on a positive note there are some new things to see. Like the new sheepshead (below).

 Sheepshead in our piling exhibit

Sheepshead - a species of porgy - are notoriously aggressive and "nippy" towards other fishes, and therefore not an ideal tank mate. However the striped, feather (pictured below), and seaweed blennies in piling are no picnic themselves, so they reach territorial stalemates of sorts.

Feather blennies defend small home territories, such as this whelk shell

One of the downstairs exhibits that was unfortunately damaged, was our jelly exhibit. we previously exhibited sea nettles and prior to that lions mane, but now after the flood we are back to moon jellies. 

Sea nettle (Chrysaora quinquecirrha)

Lion's mane (Cyanea capillata)

Moon jellies are much more passive swimmers than the other two species, and also require planktonic food or foods prepared very small.The other jelly species were hand fed bits of fish and shrimp, but now we will again hatch Artemia nauplii or "brine shrimp" for them to feed on twice daily. We acquired them from a generous swap with National Aquarium in D.C. (thanks to Nick L.) and Baltimore  (Jennie J. and Andrew P.)!

Moon jellies (Aurelia aurita)

We also will be debuting the shrimp exhibit described in the last blog. Previews have been outstanding so far. And in our Mountain Cove, we have retired our large rainbow trout and brook trout in exchange for some smaller trout. Some of our broodstock went out to stud at the hatchery and a few remain here in the non-public portion of the exhibit (hint: they can still be seen from the upper viewing deck). The new trout are excellent eaters - as most trout are - and growing quickly. These hatchery fishes are mixed in with the trout born here last year and this in April. Next spring, some of these fish may be mature enough to start the cycle all over. One of the new rainbows is pictured below on exhibit.

















Saturday, November 3, 2012

Panaeid (the kind people eat) shrimp, take two finally!

We had created a new shrimp exhibit just prior to the flash flood that destroyed the lower level of the museum. This exhibit was one of the nine exhibits that suffered extensive damage; in fact this exhibit had to be completely replaced. So after nearly two full months it is finally back up and running.

Shrimp are largely thought of in regards to how they are cooked. Most people are familiar with the types of shrimp on a menu: fried shrimp, grilled shrimp, steamed and spiced shrimp, etc. but few people are familiar with the actual animal. In fact, the common edible “shrimp” is a catch-all term for several different species. On the East Coast, native edible shrimp species are closely related members of the Penaeus Family: pink, brown, or white shrimp named for their shell color. The habitats of these three species overlap and they can be difficult to distinguish. 
   A live version of the ever-popular shrimp Penaeus sp.

Shrimp are from an order of crustaceans called decapods - meaning literally “ten feet”- which also includes crabs, lobsters, and crayfish. Most decapods are opportunistic benthic omnivores, meaning they use their nimble legs and claws to crawl along the bottom and devour virtually anything edible. But shrimp, crayfish, and lobsters also possess extremely powerful, muscular tails which they can contract to propel themselves backwards swiftly when threatened. It is these muscular tails that entice so many; aside from humans, shrimp are the favorite prey of many animals including sea trout, drum, flounder, actually just about anything.

                                         A blue crayfish or "crawdad" in our quarantine room

The Bay populations of pink, white, or brown shrimp are not abundant enough to sustain a commercial fishery as they are most common in large numbers from North Carolina southward, but there are several species of non-edible shrimps in the Bay. Grass shrimp Palaemonetes sp. are too small for humans to eat (> 2”) but are by far the most abundant shrimp; present in massive numbers throughout the shallow water of the Bay, far up into rivers, even into freshwater.
 A grass shrimp Palaemonetes sp. eats a piece of gel

Other local shrimp species include: sand shrimp, rock shrimp, mud shrimp, snapping shrimp, mantis shrimp, et al., none of which are of any direct commercial importance and thus go largely unnoticed by humans.

            A crangon shrimp or "sand shrimp" is one of the lesser known shrimp in the Bay

And just for fun, we will throw in some non-shrimp crustaceans to keep it interesting, such as: spider crabs, calico box crabs, urchins, and even a couple of live scallops. Below is a video of our calico box crab molting be patient - it's worth it!






















Thursday, November 1, 2012

Rehab Update

Meet our newest rehab animals: two baby Eastern grey squirrels. The first was found by aquarium staff Sarah Peake while walking her dog. She brought it back to the VLM for me to take care of. At the time he was only 4-5 weeks old with eyes still sealed shut. He opened his eyes for the first time on October 20th.
The second one was brought to the VLM by a visitor a week later, and was clearly larger and older than the first. His eyes were already open, his fur was much fuller, and he took to formula feeding almost immediately. Already there is a noticeable personality difference between the two. The older one, named Rusty for his rust-colored hind legs and face, was at first very shy yet adventurous. Jack, the younger of the two, was

Baby squirrels are tough to take care of. They require a lot of sleep, and regular feeding (starting at around every two hours). They usually rely on mothers milk, which can be replaced by a dog or cat powdered formula via syringe. Later on they can take soft fruits like banana or apple, and then progress into gnawing on pecans, acorns, almonds, etc. At around five weeks of age there eyes begin to open, triggering their upper incisors to break through the gums.

So far so good! They have quickly taken to gnawing on harder foods as their teeth further emerge, and enjoy climbing up their new cage. After the winter they will be released and fully able to forage for their own food and shelter.
Feeding formula from a 1cc syringe
Jack (above) enjoys having his cheeks rubbed.
 

 - Patrycja Lawryniuk, aquarium staff



Saturday, September 8, 2012

Fall colors in fishes: darters, dace and others showing off

Fall has begun the second wave of breeding among the freshwater fishes here at the museum. Both habitariums - the Cypress Swamp, and the Mountain Cove/Stream/Lake - are exposed to natural light 24 hours a day, and also echo the natural temperature fluctuations outside.
The waterfall in the Mountain Cove habitarium

These cues trigger many of the fish species to begin their fall breeding season. Sunfishes, such as the bluegill pictured below, develop vibrant, exaggerated coloration, especially around the head and chest, in hopes of attracting a mate. The males also fan out saucer-shaped nests with their tails which they guard aggressively against rivals. If he is bright enough and has constructed a suitable nest, he might get lucky and entice a willing female to lay her eggs there, which he then fertilizes. The female's job is then done and the male remains to protect all his newly hatched offspring.

A male bluegill, aptly named for his blue gills, is in fine form over a nest

A male pumpkinseed in breeding colors

On the other side of the museum, the trout are also getting anxious to mate. Trout have a similar ritual as the sunfishes but not quite. The male will develop a hooked jaw, or kype, and even a hunched back during mating season, and his nest is called a redd. If he is able to mate successfully, he will fertilize a females eggs over the redd, but both parents will then move on with no further care for the young. 

A large male brook trout in the Mountain Cove exhibit

Many of the fishes in the stream have also begun to "color up". Mountain redbelly dace exhibit astonishing coloration to stand out in the crowd, such as the ones pictured below with rosyside dace.

A closer look at one of the mountain redbelly dace showing his colors
Blacknose dace
A blacknose dace in a shower of bubbles (middle) and a rosyside dace living up to his name

But the dace aren't the only ones showing off in the stream. Many of the darters have also begun to display there breeding colors, such as the also aptly named redline darter (Etheostoma rufilineatum) pictured below.
Vibrant male redlines, such as the one above, have even inspired an elaborate tattoo and other artwork in their honor, as compared to the female redline (pictured below) who is attractive as well, but is not as desperate for attention as her male counterparts.

This adult female redline darter can pick and choose her mate


A dominant male Roanoke logperch (Percina rex) in breeding colors (bottom) chases off two non-breeding colored males.


The snubnose darter has many subspecies that can be identified by the patterning of the males. This one appears to be Etheostoma simoterum from the North Fork of the Holston River, VA.






Thursday, August 9, 2012

Just born! Video of newborn baby seahorses - (Hippocampus erectus)

This morning at check in, we were pleased to discover that our male lined seahorse (Hippocampus erectus) on exhibit gave birth! Now there are hundreds of newborn seahorses swimming freely in the Seahorse exhibit. It is very common for our seahorses to give birth in the early morning hours, so we were looking for them during check in.
A three day old lined seahorse - approximately 1 cm long

The ventral surface of the adult male seahorse (his belly) is equipped with a pouch used for carrying eggs that the female had deposited while mating. There, the eggs are fertilized, then hatched, and the young are carried until fully developed. It becomes obvious in seahorses, as in many animals, when they are close to giving birth. This particular male was very gravid, and we knew it was only a matter of days before he gave birth!
One of the juveniles feeds on Artemia nauplii (the small white dots)

Juvenile seahorses are obviously incredibly small and in captivity, the life support system must be designed so they do not get sucked into the filtration system. They also require a very specific water flow; too much and they get buffeted about, too little and they do not feed or swim effectively. The little horses will eat enriched live zoo-plankton, primarily Artemia (brine shrimp) nauplii, until they can be transitioned to more substantial and nutritious foods.

Below is a video of the day old sea horses and some very small nauplii they are feeding on.


video

Saturday, August 4, 2012

Photos of Beaufort, NC - Trawling and dredging out of Duke





Front Street, Beaufort, NC

Shrimp Trawlers, Beaufort

 
Trawl gear off an old shrimp boat

Duke's Nicholas School for the Environment across the water from Beaufort

 The deck of the R/V Susan B Hudson

 
Sorting through the product of a box dredge from the Newport River

 Oysters, short-spined and purple urchins, sand dollars, etc.

 Patrycia apparently likes urchins

 A smooth butterfly ray Gymnura micrura in the live well prior to release

 Blackcheek tonguefish Symphurus plagiusa

 Lined seahorse Hippocampus erectus

 Northern searobin Prionotus carolinus
 
 
The view of Beaufort at night from the Duke marine lab

Beaufort may be the pinfish Lagodon rhomboides capital of the world!

Night fishing off the docks = pinfish, black sea bass (above), pigfish, spottail pinfish





Thursday, July 26, 2012

Shark Fishing on the York River - atlantic sharpnose

The Aquarium staff here at the Virginia Living Museum recently chartered a boat to obtain a shark for our Chesapeake Bay Aquarium. We were looking for a single small - around 2-3 feet long - coastal shark that is common in our area, preferably either a bonnethead (Sphyrna tiburo) or a sandbar shark (Carcharhinus plumbeus).

Aquarists Patrycja Lawryniuk, myself (Sarah Peake) and Aquarium Curator Chris Crippen, all hopped on board with Captain Alan Alexander (owner of York River Charters), who has extensive professional experience fishing this area and had been catching sharks and many other fishes for many years- so we were in good hands. Our first mission was to catch live bait (primarily Atlantic croaker, Micropogonias undulatus) needed to catch a shark. After a short run up the York River, we drifted over oyster beds that teemed with small craoker, each of us using a tandem bottom rig baited with squid on a light-weight bait casting rod provided by Capt. Alan. Chris was the first to catch a fish! We each caught several croaker (Chris unsurprisingly caught the most) and kept them in the live well on the boat. Once we felt we had enough bait we made our run downstream out of the York River and into the Bay.

Capt. Alan drove the boat for about 15 minutes before we reached York Spit, where we anchored.
There were several other boats in the distance and Capt. Alan informed us that they were probably trying to catch Cobia. We have plenty of cobia at the VLM, we needed to find a shark!
Immediately, we set our chum bucket out that we had been preparing the last couple of weeks. During food prep, we would "recycle" all of the unused fish parts into the chum bucket, add a little water here and there, and mix some larger pieces into a bloody slurry. This is a good way to attract sharks, and it was making use of every part of the fish we were already using to feed our aquariums. The 5 gallon bucket had been drilled with small hole to allow the liquid and small fish particles to drift down-current, drawing in curious and hungry sharks. We set out four lines, each baited with a live croaker on "fish finder" rigs - circle hooks on a shock leader that allows the line to slide without resistance that may alert a fish trying to take the bait. After each of the rods were anchored into slots on the sides of the boat...we waited.
Sarah and Patrycja waiting patiently for a bite
 After what felt like forever (it was actually only about 15 or 20 minutes) one of the lines began to tug. We all stood up quickly with excitement. We had agreed that I would get the first "take" or to be the one to fight the first fish. I strapped on a fish belt and locked the rod into place. With a little more effort than anticipated, I reeled the shark in.
Sarah reeling the shark in while Patrycja waits in excitement.
Once the shark was close enough to be visible from the surface, we wanted to identify the species as quickly as possible. We could see right away that it was not the species we wanted; I had caught an Atlantic Sharpnose Shark. She was a beautiful female, about 36 inches in length and approximately 6 pounds. Although she was not the target species, we were still happy to have gotten our first catch. After quickly taking a few photos, we immediately returned her to the water. At this point, we were glad the sharks were taking the bait!
Sarah holding the first Atlantic Sharpnose!
We casted the line back out with new bait and waited again. What felt like an even longer wait, we were all getting a little discouraged when none of the four lines were getting bites. After another few minutes, one of the lines began to tug, except not as aggressively as the first. We reeled it in only to find a 20 inch Bluefish. He was happy to get a free meal as we threw him back into the water and casted the line back out.
After just a few more minutes one of the other lines was tugging aggressively.  Patrycja was the one to pull this line in as we watched in anticipation. (Click below to watch too!)
video
Video of Patrycja reeling in her Atlantic sharpnose

Patrycja pulling in her catch while Alan helps her release the shark from the hook
Patrycja with her catch!
It was another Atlantic sharpnose! This one was another female, and a bit smaller (about 23 inches long). We were tempted to keep it, since the size was so perfect, but we stuck to our mission and threw her back in.
We had already been out on the water for about 2 hours, and everyone could see I was feeling a little seasick. With little hope in catching any other species, Chris decided to call it a day. We motored back to Yorktown shore empty handed, but with anticipation of a better catch next time. Chris and Patrycja will be back out soon and we will all keep our fingers crossed that they bring back the perfect shark. Good Luck!

By; Sarah Peake - Aquarist at the Virginia Living Museum