Posts Tagged 'breeding'

Thoughtful Thursdays: Chesapeake Bay Lined Seahorses

Many people don’t realize that there is a species of seahorse that calls the Chesapeake Bay its home.  The lined seahorse, hippocampus erectus, lives in shallow eel grass beds during the summer and moves to deeper submerged aquatic vegetation during the winter.  It can typically be found in the lower to middle Chesapeake Bay and, in particularly dry years when the water is saltier, as far north as Kent Island and the Bay Bridge.

Lined Seahorse

Lined Seahorse at National Aquarium, Baltimore
Photo courtesy of Michael Bentley

The lined seahorse varies drastically in both coloration and ornamentation.  Individuals can range from a yellowish color all the way down the spectrum to a nearly black color.  Some may have intricate ornamentation on their backs and their heads.  Additionally, they can change color slightly to match their surroundings.  As with all seahorses, males carry a pouch which they use to hold their young after breeding.  Breeding itself is complicated, it includes a drawn-out ritual of dancing and clicking between the male and female.  At the end of the courtship, females deposit their eggs into the male’s pouch where they are fertilized and held until ready to be released (about 2 weeks).

Lined Seahorse

Lined seahorses vary in color, pattern and ornamentation

Seahorses as a whole are ineffective swimmers.  They only use three of their fins (two pectoral fins and one dorsal fin) to swim.  They beat these fins rapidly to provide propulsion, but it is not enough to keep them stationary in even the most gentle of currents.  It is because of this that they require something to hold on to.  For our local lined seahorses in the Chesapeake, that something is often eel grass, as well as other submerged aquatic vegetation.  These grasses are vital to the seahorses’ ability to hunt, breed and just plain survive.  Seahorses are ambush predators and so they need something to anchor themselves to while hunting.  As they hide, prehensile tails attached to the eel grass, they wait for prey to float by their snouts.

lined seahorse

Lined seahorses have very small fins, making it hard for them to swim.

Unfortunately, eel grass is in trouble in the Chesapeake Bay.  Nutrient pollution from farms, sewage and other human activities often leads to large algal blooms, which grow near the surface of the water and block light that the grasses need to grow. Additionally, destructive fishing techniques like bottom trawling can rip up huge swaths of submerged aquatic vegetation, causing wide-spread loss of habitat.  Because they are so specialized in their habitat needs, lined seahorses have little hope of successfully hunting and breeding without the grasses.  These pressures are threatening seahorses worldwide. As a result of these and other conservation pressures, it is estimated that the world’s lined seahorse population has declined by at least 30 percent in the past 10 years. We must begin to take steps to preserve the local habitat, or we risk losing this very interesting and important Chesapeake Bay species.

What you can do to help:  Reduce waste runoff, which pollutes waters like the Chesapeake Bay.  

  • Control insects using natural controls instead of pesticides. Americans directly apply 70 million pounds of pesticides to home lawns and gardens each year and, in so doing, kill birds and other wildlife and pollute our precious water resources.
  • Dispose of motor oil and anti-freeze through a local service station or recycling center. A one-quart container of oil disposed of at the local landfill can contaminate up to 2 million gallons of drinking water and the water home of our seahorse friends.
  • Don’t pour anything down storm drains because they lead to the bay, which connects to the ocean. Most sewer systems and wastewater treatment plants do not remove poisonous cleaners, and yard and car-wash chemicals make their way into local waterways, and, eventually, into our ocean, harming animals along the way. You wouldn’t want to swim in those chemicals, and neither do animals!
  • Learn more!
    To find out more about the lined seahorse and the troubles threatening them in our area, listen to this special seahorse edition of WYPR’s Environment in Focus with Tom Pelton

New chicks on the block!

From Ken Howell and Deb Dial, Rain Forest staff -

We are happy to introduce the newest members of our Rain Forest bird collection: two bay-headed tanager chicks!

Newly hatched bay-headed tanagers! Photo by Alex Zelazo-Kessler

This is the first successful rearing of bay-headed tanagers in our Upland Tropical Rain Forest exhibit. Rearing small passerine birds in a mixed species exhibit (such as ours) is extraordinarily difficult, so we are very proud of this success! It has taken several years of intuitive problem solving by our aviculture staff to reach this point. In case you are wondering, aviculture is the practice of keeping and breeding birds and the culture that forms around them. 

The goal of our aviculture staff is to provide an environment in the Rain Forest that promotes natural behaviors, which we hope ultimately leads to parent-reared, on-exhibit reproductive success.

Because we are attempting to breed on exhibit, the birds here experience many of the same challenges that chicks and parents experience in the wild. We have encountered problems with other species predating on the eggs and have had to deal with newly hatched chicks and their parents selecting inappropriate food items. Perhaps the greatest difficulty has been that there are very few opportunities for staff to learn from each breeding event (usually just two to three events a year). 

The breeding success is due to a combination of adaptations, which have been implemented one at a time over the last several years to judge the effectiveness of each change. Those adaptations have included the creation of “exclusion boxes” to prevent nest interference, the introduction of new food items over time, and the installation of nest cameras to maximize our potential to learn more about the breeding processes!

Our two new chicks have been named “Billy” and “Kline” in honor of the Aquarium’s Facilities director, Bill Kline. He was of great assistance in delaying a project to repair the Rain Forest deck, which was scheduled to begin the very day the eggs hatched! Though the nest is about 2-3 feet away from the intended work space, we wanted to give the chicks some undisturbed time to become acclimated to their new world.

The actual gender of the young birds is currently unknown and will be determined by DNA analysis at a later date. The chicks, along with their parents, are currently residing in the corner Howdy cage where the young birds can practice their flying skills. It is our plan to release the new chicks into the Rain Forest exhibit once they have become experienced fliers.

We have had success breeding other species, including Red-capped Cardinals and White-tailed Trogons. In fact, we have led the industry in White-tailed Trogon breeding and have been able to provide many other institutions with information to help them do the same. We hope that with continued and consistent success with our small birds on exhibit, we will become a leader in tanager breeding as well!


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