Saturday, June 25, 2011

Unusual - but very cool - fishes

There are over 20,000 fish species inhabiting every possible aquatic habitat, so there are some very strange fishes out there. Even in this area, there are many unusual fishes that are relatively abundant, but the average person does not often see. Some of the fishes like the northern stargazer (pictured below) are ambush predators and bury in the sand, so they are deliberately hidden from view.
Others, such as searobins, are often associated with structure, deep water, or active primarily at night. There are a few species of sea robins in Virginia, most common are the northern searobin and the striped searobin (pictured below).

Searobins are occasionally caught on rod and reel while bottom fishing and despite being a good (but small) food fish are nonetheless considered a "trash fish" or nuisance by anglers.

Both these fishes are exceptionally beautiful and have highly modified structures. Stargazers have an electrical organ behind their eye that is thought to be used to stun prey. They also have venom glands at the base of their pectoral fins for defense. Stargazers as so named for the positioning of their eyes that look skyward to locate prey moving overhead as they are entirely buried in sand. Once prey is located, stargazers create enormous suction with their huge mouths and engulf their victims; a move that is almost too fast to see.

Searobins have a large bony head with a duck-like mouth and very specialized pectoral fins. The foremost pectoral fin rays are detached and singular; they can use them like fingers to stir up substrate and locate prey. The remainder of the pectoral fins are very broad and brightly colored (as seen on a northern searobin below). Also they are able to produce sounds through the contraction of muscles surrounding their swim bladder  and - similar to a croaker or oyster toadfish - they are known to croak or grunt loudly when caught.

Thursday, June 16, 2011

More jellies and the lemon sharks claim their first victim

Jellies are standard display animals at public aquaria due to their beauty and downright strangeness. But they are difficult to culture and even more difficult to procure from another institution via trade. So as a short-cut we have been collecting them and displaying what is seasonally available. Right now the resident jelly - and therefore the one currently on display - is the sea nettle Chrysaora quinquecirrha. They are notorious around the Mid-Atlantic for ruining beach outings with their irritating stings, but they are beautiful and plentiful at this time of year. Hopefully, later in the year we will be able to collect and display my local favorite the cannonball jelly Stomolophus meleagris. They are much more difficult to collect as they are very fast swimmers and have excellent senses that allow them to avoid capture; so much so they seem to see you coming and head the other way, quickly!

A sea nettle on display at the VLM

Today marks the first official casualty due to lemon shark aggression. After I performed the routine check-in for the upper level of the building, which includes cleaning the acrylic on the Chesapeake Bay Aquarium, and all seemed well, I was called to the tank by a staff member. A spadefish lay mortally wounded with four large softball-sized chunks removed from it. Apparently, the lemon sharks got hungry and decided to feed themselves. This is problematic on a few levels. Now the sharks have had success devouring a tank mate. There have been bite marks on others but until now all had survived. Also, I value all the animals here including the spadefish and never want to expose animals to uneccessary injury or death. I have raised or collected all of the spadefish (and most of the other species as well) at the VLM and feel responsible for the well-being of each. And lastly, I dive with the sharks, alone for now, and must have a renewed awareness of their activity during dives. While I certainly am not afraid of them at this point, I also do not want to experience the loss of any softball-sized chunk out of me. And as they grow the issues will only escalate.

Saturday, June 11, 2011


Virginia has many ponds and all of them contain a surprising amount of life. Ponds are generally defined as water bodies that are shallow enough for sunlight to reach the bottom. Therefore, they are often covered with and full of aquatic vegetation and plankton, making them great places for small fishes, amphibians, and insects to live and reproduce. Duckweed, waterlilies, parrot feather, pickerel weed, cattails are all common pond plants and hide many of the pond's life from our view, but also provide complex underwater habitats.

Duckweed and parrot feather cover a pond's surface

Ponds may experience drastic seasonal fluctuations in temperature and oxygen levels, so the fishes that live there must be adaptable and hardy. Common pond fishes include mosquito fish, largemouth bass, bullhead catfish, several sunfish species, and one or more pickerel species. Of these, there are two species that are especially beautiful, and even more elusive: the redfin pickerel (Esox americanus) and the bluespotted sunfish (Enneacanthus gloriosus).
A pickerel lurks in vegetation

A male bluespotted sunfish

Neither of these fishes get very large, but more than make up for it in style. The redfin pickerel is most often under 8 inches or so and the bluespot reaches only around 4. Both are relatively common in southeastern coastal ponds.

Redfin pickerel are the smallest member of the pike family which includes the musky, northern pike, and the most common chain pickerel. Although they are small, they are as voracious as their relatives, gorging on almost anything they can swallow. As ambush predators they spend most of their time motionless and hidden in vegetation; additionally they are mostly too small to be caught by anglers and thus are rarely seen.

Blue spotted sunfish are shy fish that also stick close to vegetation and woody debris. Despite their shy nature the males display very flamboyant iridescent blue spots, giving them their name. They feed mainly on small invertebrates.

Saturday, June 4, 2011

I want to do what you do!

We recently had two long-time employees, Jessi Shupe and Heidi Pankratz, move on from the VLM to new opportunities. While it is hard to lose good employees and even harder to replace their knowledge immediately, we are happy for them. The two positions have recently been filled and we look forward to working with them. There were many, many strong candidates but the two chosen were ultimately picked because of a combination of character, personality traits, and experience. The amount of responsibility that will be bestowed upon them is significant and I follow a personal philosophy of hiring people that will grow into the position and that have already proven a significant amount of dedication to doing this type of work.

Guests at the museum, often on my behind the scenes tours, ask how did you get this job? or what do you suggest for me (or my child) to do to get into this type of work? My first suggestion is to actually do it - for free as a volunteer - to see if it the reality of the job is interesting or stimulating to pursue; this is important because NOBODY is in this for the money! My second suggestion is to do well in school in the biological sciences (a BA/BS in biology or related degree is required for employment) and get some experience somewhere. Understand that there are many people with a degree, but their experience is what differentiates the candidates. So once you have the degree and experience, be patient and flexible. Always do something as closely related to what you want to be doing as possible; working at a bookstore may pay the bills but stay connected to the work in anyway possible. Every employee of mine over nearly 7 years were volunteers of mine first, except one, who volunteered at the GA Aquarium an entire summer for free.

One of the two Lemon sharks brought down from Connecticut.

So what can you expect? A lot of mundane tasks, routine work, and virtually no recognition for the amount of work and responsibility invested. BUT you also experience things that very few people get to experience. A short list of my personal experiences related to one exhibit (Chesapeake Bay Aquarium - CBA) in the past year: driving our loggerhead 19 hours straight to her new home in Dallas TX almost exactly one year ago today and nearly 5 years after driving her as a juvenile sea turtle from TX, putting her in a bathtub in Mississippi overnight, SCUBA diving over 200 times with her, raising her to nearly three hundred pounds. Then bringing another loggerhead from NC that weighed only 5 lbs as a replacement (eventually put in the Chesapeake Bay Aquarium at 26 lbs, Fall 2010); removing two 6 foot nurse sharks (due to their size)acquired over 5 years ago from a pet store at 14" and raising and diving with them; releasing a sandbar shark from CBA we raised named "Hank" after the friend of mine who caught him; driving 2 lemon sharks (currently on exhibit), from Mystic, Connecticut this winter to replace the sandbar shark; releasing two southern stingrays that were originally pupped ( at ~10") at the National Aquarium and raised until they were nearly 3 feet across (because the lemons would eat them), and acclimating three 15 pound striped bass (currently in the James River exhibit) raised from 4 inch juveniles from freshwater to full saltwater to then be added to CBA. This is but a portion of the work involved with this particular exhibit. There are 3 weekly water changes, a weekly dive for interior cleaning, weekly maintenance on the life support, daily sea turtle feedings, lemon shark feeding 3 times a week, the fishes are fed for public program 4 times a week; all of which requires supporting work such as food prep, water chemistry, daily bicarb additions, etc.

Christi, on her way to Dallas Texas to her new home.

Striped bass that will be moved into the CBA tank
So...if you think you want to do this type of work, try it. If you like it, stick with it. Patience and hard work still matter; raising animals requires it.