Juvenile sandbar sharks - video!

We recently acquired two sandbar sharks (Carcharhinus plumbeus);one male and one female. They are in quarantine at the moment and may not be on display for a while, but this video provides a sneak peak. The smaller of the two is a female and likely only a couple of months old. More about where/how we got them, details about their care, and what we have planned for them very soon...

Blenny fight! A dominant male protects his food (little neck clam)

A dominant male (blue spot on the dorsal) fights others away from the freshly shucked clam in our piling exhibit

Feather blennies are named for the two cirri or "feathers" over their eyes

Blennies, feather blennies in particular, are feisty little fishes (as seen in the video). Blennies are a group of small saltwater fishes that remain around relatively shallow water structure, such as oyster reefs and pilings throughout their entire lives. Once they have established a territory, they vigorously defend it and often battle each other in close quarters for food and mates. Productive habitats may house a blenny or mated pair of blennies every couple of square feet, each patrolling their respective property with head up and fins extended ready to scrap. One reason they defend their territory so aggressively is that prime real estate is hard to come by and even harder to get to. These pugnacious little fishes are not strong swimmers, rather they rest upright on their broad pectoral fins and use their broad rearward fins to propel them quickly forward in lightning fast bursts - usually at a trespasser on his territory - and not for long distances.

Striped blennies often lay on their sides inside seashells

There are a few other species of blennies occasionally found in Virginia, but the most common by far are the feather blenny Hypsoblennius hentz, and the striped blenny Chasmodes bosquianus. Though these two are related, the striped blenny is a much less aggressive species and therefore easier to house in an exhibit with other species. They often are found in proximity to each other and a host of other species as well.

Naked gobies can often be found with blennies among oyster shells

Oyster reefs and grass beds are important habitat for a huge variety of similar fish species such as the naked goby, skilletfish (above - pictured stuck on the acrylic with a "suction cup" on its belly) and the much maligned oyster toadfish (a pile of them pictured below)

 Innumerable crabs and shrimps also hide in the nooks and crannies of the oyster shells. 

      

 Grass shrimp, sometimes called ghost shrimp are an important prey species

All these animals occur in such densities because there is an enormous amount of prey and forage items available in these areas, mainly invertebrates and algae. These structure communities in turn attract a multitude of predatory fishes attracted to a high concentration of prey. Fisherman may not be aware of exactly why oyster reefs draw sea trout, red drum, croaker and stripers, but they certainly know that they do. We attempt to represent these structure-based communities in our "Piling" exhibit that showcases blennies, gobies, skilletfish, sheepshead, scup and a variety of crab species.But as noted earlier the feather blennies rule the tank, nipping at fins and challenging much larger fishes, making it difficult to display more than a dozen or so fishes at a time.

Video of "teenage" lined seahorses (H. erectus) feeding

Our "baby" seahorses are growing up. Since they were born several months ago, each of these lined seahorses has grown considerably and they have all begun to take on individual characteristics. As seen in this video, they display a wide variety of colors, patterns and even sizes. Lined seahorses use their colors, elaborate patterning and fleshy appendages to hide amid submerged aquatic vegetation (SAV) which were once much more common and wide-spread throughout the Bay. Micro-communities live in and actually on the leaves of aquatic vegetation - called epiphytes - that support and house a surprising number of small organisms, especially amphipods, and a variety other small invertebrates upon which seahorses feed.
In captivity they are fed enriched P.E. Mysis, live Artemia and Cyclop-Eeze throughout the day.

During the next stage of development these adorable little fishes will begin to mature sexually and we can then finally tell how many males and females were born. Seahorses are sexually dimorphic - males and females are physically different externally - and the male can be discerned by a large leathery brood pouch on the front of his torso. These animals are part of the Line Seahorse SSP (Species Survival Plan). The VLM and many other zoos and aquariums across the country within the AZA community captive breed and exchange lined seahorses to ensure they are genetically diverse and that there will be no need to capture any wild lined seahorses for display. Look for some of the larger juveniles to finally go on public display with the four adults (pictured below) already on display in our seahorse exhibit in the Chesapeake Bay gallery.

Seahorses like to hang around together

Jellies - by Aquarist Patrycja Lawryniuk

Jelly hunting is an work activity that I enjoy the most! Every year the aquarium staff collects jellies from the local waters near to the VLM, such as the York River. Certain jelly species are seasonal and tend to show up in the area at different times of the year. The large colorful lion's mane jellies Cyanea capillata are actually arctic and prefer colder water, and therefore appear in late January to early March. The white jellies that haunt the summertime waters are sea nettles Chrysaora quinquecirrha, which are famous for their stinging tentacles. We can usually rely on sea nettles popping up in early June when the waters start to warm up. However, an unusual amount of heavy rains have kept water temperatures low and pushed their arrival back a few weeks. Since sea nettles are so common in the Chesapeake Bay, the National Oceanic and Atmospheric Administration (NOAA) tracks the ideal conditions for these jellies in the bay, and we are able to view their abundance online!  Finally, in the last two weeks, we hit the jelly jackpot at Grandview Beach in Hampton.

Sea nettles are generally much smaller than lion's mane jellies, but are faster and more aggressive. Their sting can be deadly to their prey, but is no more than a painful irritation to humans and can be neutralized with a small amount of vinegar. Nettles are carnivorous, usually feeding on zooplankton, other jellies, and even small fishes! On exhibit we try to emulate their natural diet as closely as possible. They are fed minced  capelin, shrimp, or squid, with an enriched commercial food called Cyclop- Eeze The prepared food is then mixed with salt water and distributed to each jelly using a turkey baster. Lion's mane are larger and slower, and their sting is not quite strong enough to irritate human skin, therefore they are fed with larger pieces of food which is distributed individually into their tentacles using tweezers.Moon jellies are planktivorous and are fed Artemia nauplii or newly hatched brine shrimp.

Saltwater collecting season: juvenile lookdowns, sea robins, flounder, etc.

 A summer flounder (~ 2 inches long)

As the weather warms up, the aquarium department takes full advantage of our brief opportunities to catch all the saltwater fishes we will need until next year. Early summer is an excellent time to collect, not only because of the weather; a wide variety of juvenile fishes frequent the shallows as they begin to prey on invertebrates, micro-crustaceans and larval fishes close to shore. These miniature predators are voracious and eat constantly to fuel their rapid growth. Come fall they must be large and healthy enough to survive among the big boys when they will either migrate southward or move into deeper water. During the summer we are able to collect a wide variety of species: summer flounder, lookdowns, puffers, sea robins, black sea bass, jacks with a beach seine, sometimes in the same haul! Many of these species would be much more difficult to acquire as adults, so we seize the opportunity to catch them while we can. There are several benefits to collecting fishes as juveniles - other than convenience - but most importantly juveniles acclimate to captivity much more readily than adults. Below are just a few of the juvenile fishes we collected this season with (hopefully) many more to come.

Juvenile bluefish

 Juvenile lookdown (approximately the size of a quarter)

Juvenile sea robin

Juvenile northern puffer

Juvenile black sea bass

Candy darters (Etheostoma osburni) in Big Stony Creek

Below is a short video of the elusive candy darter, native to the New River drainage.

Virginia has an excellent variety of native fishes primarily due to the diversity of aquatic habitats. Several large Chesapeake bay tributaries begin on the eastern slope of the Appalachians as cold upland creeks, gaining volume and strength before emptying into the Bay. Headwaters may begin as a native brook trout stream but their ecology may change drastically, ultimately ending up (like the mighty James River) miles across and home to oyster reefs and a variety of saltwater species. But many Virginia rivers and streams do not end up in the Bay. In the western portion of the state, several large rivers - the North and South Forks of the Holston, the Clinch and the Powell - are part of the Tennessee drainage, while the ancient New River flows northward into West Virginia and becomes part of the Ohio drainage. The Roanoke River flows southward into North Carolina and ends up in Albemarle Sound. 

Roanoke logperch are native to just a few small sections of water in Virginia

Each of these rivers and drainages have a unique geological and cultural history, but also have fish species unique to them alone.Unfortunately, many of these species have evolved to rely upon their specific habitats within these rivers. Over time they may become isolated in an ever shrinking portion of habitat within their native rivers. An excellent example of this is the Roanoke logperch; this Threatened and Endangered species suffers primarily from habitat loss and degradation related to human activity along the banks of the Roanoke. The constriction of habitat often begins the slow doom of such creatures that literally have nowhere else to go. Not only are these fishes in jeopardy, but the cold, pristine streams they require is also getting harder and harder to find.

 The candy darter Etheostoma osburni is truly eye candy to native fish lovers

Recently Nick Little, Senior Aquarist for the National Aquarium in D.C. and I went in search of one of the rarest and arguably the most beautiful of all the darters, the candy darter Etheostoma osburni. This darter is native only to the New River drainage and is found in such limited areas and small numbers that it is listed as a Species of Special Concern, and is protected by law. We were driven by the desire to see these beautiful animals for ourselves, alive in their own habitat before they are gone. This may sound dramatic, but each year at least one spot I have previously enjoyed has been bought, bulldozed, or altered in the name of progress.

 

A pristine tributary of the New River

Although we are prohibited from collecting or displaying this species, as darter enthusiasts (nerds) the challenge was to find them, and then film them underwater.Unfortunately for us, they like gravelly beds in swift water, so our videos reflect the fact they are far more suited to such habitat than a couple of dudes in wet suits with one hand on a camera and 50 degree water flowing down your front.

Nick finds his soul mate; a female candy darter resting in the depression atop this rock

A male candy darter in the photo box

I put one of the photo boxes into action

Aside form the obviously beautiful candy darter there were many other excellent fishes, among them: the fantail darter, the Appalachia darter, mountain redbelly dace, an extraordinary population of crayfish, and the crescent shiner.

Appalachia darters are also native only to the New River system

Seahorse breeding tank - babies meet parents!

Today we removed the partition that separated the lined seahorse parents from their young and they mingled together for the first time. The partition protected the young from being sucked against or into the filter system. As the video shows, the juveniles are two different ages; about three months apart. Seahorses love to cling to each other with their tails and often form chains of three or four seahorse all connected together, often attempting to move in different directions at the same time. In the above video they are feeding on live adult Artemia or brine shrimp, which they get many times a day, but also are fed Cyclopeeze and Mysis. Its easy to tell from the video why people like seahorses so much; they have a gentle and inquisitive nature - and are just a bit silly.