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orange cup coral

Orange Cup Coral (Tubastraea coccinea)

Cup Coral and Brain Coral

Brain Coral (top) and Cup Coral (bottom)

I just found out that one of my favorite hard corals, the Orange Cup Coral (Tubastraea coccinea), is considered an invasive species.

Orange cup corals are beautiful brightly colored orange corals with flower-like yellow tentacles that extend at night or in areas of low light.

Although the orange cup coral is a hard coral, it’s not a reef-building coral. Also, unlike other corals, the cup coral, does not depend on the symbiotic algae, which shares it’s photosynthesis-created food with the coral animal. Because of this, the cup coral can grow in dark places such as shaded walls, caves and underneath overhanging ledges.

I first noticed orange cup corals on the walls of an rocky indentation on the Tektite snorkel and again on the walls of the caves at Norman Island. Now I see them elsewhere even on the Trunk Bay Underwater Trail.

Cup corals do not seem to be a major problem here in the Virgin Islands as they seem to prefer the darker areas that other corals don’t like and I’ve not seen any great proliferation in all the years that I have been snorkeling around the Virgin Islands.

They are, however, a problem in the Gulf of Mexico where they tend to crowd out other native coral and sponge species. They especially like oil rig platforms where hundreds of thousands of colonies may be found attached a platform.

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I have always enjoyed the melodious song of our tiny native tree frogs. The symphony begins around sunset and continues until dawn. It is a love symphony, meant for male frogs to attract the attention of nearby females.

Our island now hosts another species, the Cuban tree frog. They have a reputation of being toxic, even to the touch. Cannibals, they eat the native frogs, but worst of all is their abominable screeching.

 

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The Aedes aegypti mosquito

From the Center for Disease Control, San Juan:

The Aedes aegypti mosquito can transmit the viruses that cause dengue fever and chikungunya. The female mosquito lays eggs in containers with water and plants near the home. It bites people and animals. This species can survive year round in tropical and subtropical climates.

General Information
Aedes aegypti is a small, dark mosquito with white lyre shaped markings and banded legs. They prefer to bite indoors and primarily bite humans. These mosquitoes can use natural locations or habitats (for example tree holes and plant axils) and artificial containers with water to lay their eggs. They lay eggs during the day in water containing organic material (e.g., decaying leaves, algae, etc.) in containers with wide openings and prefer dark-colored containers located in the shade. About three days after feeding on blood, the mosquito lays her eggs inside a container just above the water line. Eggs are laid over a period of several days, are resistant to desiccation and can survive for periods of six or more months. When rain floods the eggs with water, the larvae hatch. Generally larvae feed upon small aquatic organisms, algae and particles of plant and animal material in water-filled containers. The entire immature or aquatic cycle (i.e., from egg to adult) can occur in as little as 7-8 days. The life span for adult mosquitoes is around three weeks. Egg production sites are within or in close proximity to households

Aedes aegypti historically is considered to be a primary vector of viral diseases such as dengue fever, chikungunya and yellow fever.

Habitat
Aedes aegypti is extremely common in areas lacking piped water systems, and depend greatly on water storage containers to lay their eggs. Male and female adults feed on nectar of plants; however, female mosquitoes need blood in order to produce eggs, and are active in the daytime. Eggs have the ability to survive drying for long periods of time, allowing eggs to be easily spread to new locations. Artificial or natural water containers (water storage containers, flower pots, discarded tires, plates under potted plants, cemetery vases, flower pots, buckets, tin cans, clogged rain gutters, ornamental fountains, drums, water bowls for pets, birdbaths, etc.) that are within or close to places where humans live are ideally larval habitats for this mosquito. This species has also been found in underground collections of water such as open or unsealed septic tanks, storm drains, wells, and water meters.

Biting Behavior
Aedes aegypti bites primarily during the day. This species is most active for approximately two hours after sunrise and several hours before sunset, but it can bite at night in well-lit areas. This mosquito can bite people without being noticed because it approaches from behind and bites on the ankles and elbows. Aedes aegypti prefers biting people but it also bites dogs and other domestic animals, mostly mammals. Only females bite to obtain blood in order to lay eggs

Mosquito Control

Check your yard weekly for water-filled containers.

Throw away or recycle water-holding containers that are not needed.

If empty containers or large objects, such as boats or old appliances must be stored, they should be covered, turned over or placed under a roof that does not allow them to fill with water.

Clean and scrub birdbaths and pet-watering dishes weekly and dump the water from overflow dishes under potted plants and flowerpots. Check that gutters are not holding water and cover rain barrels with tight screening so that mosquitoes cannot enter.

Fill tree holes and other cavities in plants with sand or soil.

Check for hidden bodies of water such as wells, septic tanks, manholes, clogged drains, etc.

Call the health authorities when you detect unusual numbers of mosquitoes. Avoid mosquito bites Use personal protection to avoid mosquito bites.

Wear long sleeve shirts, long pants, socks and shoes when mosquitoes are most active.

Apply repellents such as DEET, picaridin, oil of lemon eucalyptus or IR3535 only to exposed skin and/or clothing (as directed on the product label). Do not use repellents under clothing. In addition to wearing repellent, you can protect yourself and your family by taking these precautions:

Use mosquito netting over infant carriers, cribs and strollers.

Install or repair window and door screens to keep out mosquitoes.

Dengue Branch, San Juan, PR:
For more information please contact Centers for Disease Control and Prevention
1324 Cañada Street, San Juan, Puerto Rico 00920
Telephone: 787-706-2399
Email: cdcinfo@cdc.gov
Web: www.cdc.gov

 About Fogging

Virgin Islands Daily News

In recent weeks, the public in the U.S. Virgin Islands has criticized the territory’s Health Department for not turning to a method of prevention known as truck-mounted fogging, during which trucks travel to specific areas where mosquitoes are known to be and emit a chemical fog that kills the adult mosquito population.

However, the Health Department refuses to use that the strategy for a number of reasons.

Studies in other areas have shown that truck-mounted fogging is ineffective in killing Aedes aegypti mosquitoes, the mosquitoes which are responsible for spreading chikungunya and dengue, another mosquito-borne virus common in the territory.

The Aedes aegypti mosquito is known to remain indoors, which means it is difficult to reach via fogging.

“These mosquitoes are in our closets and under our beds. When we’re spraying from our trucks, it’s just not getting to them,” said Dr. Brett Ellis, an entomologist with the Health Department.

These mosquitoes also are known to bite more aggressively during the daytime, though fogging is more often conducted during the evening, he said.

“I’m not saying chemicals don’t work on mosquitoes, they just don’t work on these mosquitoes,” Brett Ellis said.

The fogging has been used in the past, but, additionally, scientists have discovered that the chemical, permanone 30-30, is unstable in water and the Environmental Protection Agency has raised concerns that is could contaminate rain and cistern or well water, according to Health officials.

A recommendation from Fran Jacobson, C.N.M – Cruz Bay Family Practice

Fran reports good results from a product called My Mosquito Deleter. I will be ordering one and testing it. Stay tuned…

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Chocolate Hole Sunrise

St. John Virgin Islands News

Chickengunya is officially an epidemic. I personally know several people who have or have had the illness. Their symptoms were such that it is highly probable that their problem was chickengunya, but none of them sought treatment or were tested. My point is that the problem is way worse than the reported numbers. The Virgin Islands Daily News has an excellent article which explains some important facts about the disease like why fogging won’t help and what steps one can take to minimize one’s chances of catching the illness and an explanation of how the epidemic will someday peak and then wane a phenomena called “herd immunity.”

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sea-wasp-9You’ll need to look carefully to see the translucent jellyfish in the above photo, but seeing it in the water is even more difficult. It has a dome shaped head and four tentacles. It’s a sea wasp. It stings hard and it’s hard to avoid. If you are unfortunate enough to get stung, pour vinegar on the the affected area and in severe cases seek medical attention.

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 angel-9  evil twin-9
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Chickenette (Also known as pitaya and dragon fruit)

St. John and Virgin Islands News

I met two people yesterday who just recovered from a bout with what we strongly suspect was Chikungunya. Read Virgin Islands Daily News article: Chikungunya spreads on St. Thomas, St. John

 

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upsidedown jellyfishI saw quit a few of these strange jellyfish while snorkeling the southwestern side of Maho Bay. They were resting on the bottom in about ten feet of water. While most jelly fish swim around with their head up and tentacles down, the Cassiopea spends most of its time with its’ head down resting on the sea floor and with its tentacles extended upward, hence the name, upsidedown jellyfish.

The upsidedown jellyfish can give divers a mild sting, which can be very itchy. According to Wikipedia: “The stinging cells are excreted in a mucus; swimming over the jellyfish (especially using swim fins) may cause transparent, essentially invisible, sheets of this mucus to be lifted up into the water column, where they are then encountered by unsuspecting swimmers,” but being that these jellies were in fairly deep water, this shouldn’t be a problem for snorkelers observing them.

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celtic ross-Annaberg Sugar MillFriends of the National Park guides showed me something that I had never noticed before, a Celtic cross on the top of the Annaberg Windmill. The most likely explanation for this would be that it was ordered by the owner of the estate, James Murphy, who had originally come from Ireland.

St. John and Virgin Islands News

New property valuations to appear on forthcoming bills

Tropical Wave Bringing Wet, Gusty Weather Thursday Night

Overflow Crowd Says No to St. John Marina Proposal

 

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Feather Duster Worm (Sabellidae)

feather duster wormThis creature has always fascinated me. When I first saw one, I thought it was some sort of underwater flower, and I was certainly surprised to find out that it was not only an animal but a worm. What looks like the flower’s petals are tentacles, which filter plankton from the seawater for food and increase the amount of oxygen that the worm can absorb. When hungry fish or a snorkelers finger come too close the tentacles retract to the safety of the tube that gives the species the name, tube worm. If a fish is faster than the worm and bites off some tentacles, the worm will regrow the lost parts. The tube is fashioned from parchment, sand, and bits of shell that is permanently affixed to a rock, coral or some other substrate by a sticky mucus secreted by the worm.

St. John and Virgin Islands News

USVI athletes vs. the world

St. John Weather

Mainly sunny to start, then a few afternoon clouds. Hazy. High 81F. Winds E at 15 to 25 mph.

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Brought to you by Gerald Singer, St. John US Virgin Islands (USVI)