Hurricane Season has arrived

Hurricane Season has arrived

The lineup of 2020 tropical storm names. Tropical storm “Cristobal” is currently headed towards the northern Gulf of Mexico. Photo credit: The Weather Channel

This past March, many people spoke about sensing a sort of free-floating anxiety, waiting for potential disaster to land at their doorstep. The unknowns we faced as COVID-19 cases increased in the United States were not quite like anything we’d previously experienced, although it felt comparable to knowing a hurricane was about to make landfall. After this virus, perhaps, a hurricane seems like a relief—at least we know what to expect and approximately where the most damage will occur. However, big tropical storms carry with them their own set of unpredictable factors like direction and strength at landfall. But the storm-hardiness of our homes, our tree choices, smart evacuation plans—these we can control. Well-thought out precautions can make the difference between getting right back on your feet after a storm and losing almost everything.

Aluminum shutters are one of the many preventative measures Florida homeowners can include in their hurricane preparedness.
Photo: Carrie Stevenson, UF IFAS Extension

No matter how well you have planned for a hurricane, unexpected issues always come up. However, being ready can cut down on the fear and worry.
A few of those preparedness factors include:
* An evacuation plan
* A hurricane kit
* Home wind mitigation techniques
* Tree evaluation
* Wind/flood insurance
I will discuss each of these topics in depth over the next few weeks. Particularly if you are new to the area or never experienced a hurricane, be sure to review good readiness websites, check out these apps, and see which tips might be the most useful to you and your family as we enter the already-active 2020 hurricane season.

Embrace the Gulf 2020 – the nematodes

Embrace the Gulf 2020 – the nematodes

As we continue our series on marine life in the Gulf of Mexico, we also continue our articles on marine worms.  Worms are not the most charismatic creatures in the Gulf, but they are very common and play a large role on how life functions in this environment.  Roundworms are VERY common.  There are at least three phyla of them but here we will focus on one – the nematodes.

A common nematode.
Photo: University of Florida

Most nematodes are microscopic, a large one would be about 2 inches, and some beach samples have found as many as 2 million worms in 10 ft2 of sand.  So, what do we know about them?  What role, or function, do they play in the ecology of the Gulf of Mexico?

 

Well first, they are long and round – cylinder shaped.  There is a head end, but it is hard to tell which end is the head.  Round is considered a step up from being flat in that it can allow for an internal body cavity.  An internal body cavity can allow for the development of internal body organs.  Internal body organs can move large amounts of nutrients, blood, oxygen, and hormones around the body allowing the animal to become larger.  Some argue that a larger body can have advantages over smaller ones.  Some say the opposite, but either way – a large body has been successful for some creatures and an internal body cavity is needed for this.

 

That said, the nematodes do not have a complete internal body cavity.  So, they do not have a complete assortment of internal organs.  Being round reduces your efficiency in absorbing enough needed nutrients, oxygen, etc. through your skin alone and this MAY be a reason they are small.  They are very small.

 

There are free living and parasitic forms in this group.  There are at least 10,000 species of them, and they can be found not only in the marine environment, but also in freshwater and in the soil found on land.  They have played a role in the success of agriculture, infesting both crops and livestock.  Nematodes can be a big concern for farmers and gardeners.

 

The free-living forms are known to be carnivorous, feeding on smaller microscopic creatures.  They have toothed lips, and some have a sharp stylet to grab or stab their prey.  Some stylets are hollow and can “suck” their prey in.  Moving through the environment, they can consume algae, fungi, and diatoms.  Some are deposit feeders and others are decomposers.  On our farms and in our gardens, they are known to enter plants via the roots and can be found in the fruit.

The life cycle of the human hookworm.
Image: CDC

The parasitic version of nematodes has been a problem for some species.  In humans we have the hookworms and pinworms.  Dogs have their heart worms.  An interesting twist on the parasitic nematode way of life, compared to flatworms like tapeworms, is their lack of a secondary (or intermediate host).  The entire life cycle can take place in the same animal.

 

Females are larger than males and fertilizations is internal.  Males are usually “hooked” at the tail end and hold on to the females during mating.  About 50 eggs will be produced and released into the digestive tract, where they exit the animal in the feces and find new hosts either by the feces being consumed or drifting in the water column.

 

There multiple forms of parasitism in nematodes.

–          Some are ectoparasites (outside of the body) on plants.

–          Some are endoparasites in plants – some forming galls on the leaves.

–          Some infest animals but only as juveniles.

–          Some live-in plants as juveniles and animals as adults.

–          Some live-in animals as juveniles and plants as adults.

It would be fair to say that many forms of marine creatures have nematodes living either within them, or on them.  Some can be problematic and cause disease; some diseases can be quite serious.  Others play an important role in “cleaning” the ocean, filtering the sand of organic debris.  Many have heard of nematodes but know little about them.  Either good or bad, they do play roles in the ecology of the Gulf of Mexico.           

Embrace the Gulf 2020 –  the Nemeratean Worms

Embrace the Gulf 2020 – the Nemeratean Worms

As we embrace the marine life of the Gulf of Mexico during this year of “Embracing the Gulf”, we are currently hooked on worms.  In the last article we talked about the gross and creepy flatworms.  Gross because they are flat, pale in color, only have a mouth so they have to go to the bathroom using it – and creepy in that many of them are parasites, living in the bodies over vertebrates (particularly fish) and that is just creepy.  You may ask why would we even “embrace” such a thing?  Well… because they do exist and most of us know nothing about them.

A nemertean worm.
Photo: Okinawa Institute of Science

This week we continue with worms.  We continue with a different kind of flatworm.  They are not as gross, but maybe a little creepy.  They are called nemertean worms and I am pretty sure (a) you have never heard of them, and (b) you have never seen one.  So why “embrace” these?  Well… again it is education.  They do exist, and one day you MAY see one – and know what you are looking at.

 

Nemerteans are flatworms.  They are usually pale in color but a different from the classis fluke or tapeworm in a couple of ways.

1)      They do have a way for food to enter and another for waste to leave, what we call a complete digestive tract – and that’s nice.

2)      They have this long extension connected to their head called a proboscis.  Many of them have a dart at the end they can use to kill their prey – and that’s creepy.

3)      And as mentioned, most are carnivores, feeding on small invertebrates – and that’s okay.

We rarely see them because they are nocturnal – hiding under rocks, shells, seaweed during the day and hunting at night.  Most are about eight inches long but some in the Pacific reach almost eight feet!

I would put that in the creepy file.

 

As we said, they are usually pale in color, though some may have yellow, orange, red, or even green hues to them.  Their heads are spade shaped and, again, hold a retracted proboscis.  This proboscis can be over half the length of the worm.  At the end is a stylet (a dart) which they can use to stab their prey (small invertebrates).  They can stab repeatedly, like using a knife, – they may stab and grab, like using a claw – or they may be a species that has toxin and kills their prey that way.
Nice.

 

Some would add this to the creepy file as well.  A long pale worm, moving at night, extending a long proboscis when they get near you with a sharp dart at the end they essentially “sting” you like a bee.

Yea, creepy.

But we NEVER hear about such things with humans.  They hunt small invertebrates like amphipods, isopods, and things like that.  If you picked one up, would it stick the dart in you?  My hunch would be yes – I honestly don’t know, I have only seen one to two in the 35+ years I have been teaching marine science and I did not pick them up.  I have never met anyone who has and have never read “DON’T PICK THESE UP – VERY DANGERSOUS”.  So, my hunch is that it would not be very painful at all.

But don’t take my word for it – again, I have rarely seen one… so, don’t pick them up 😊

There are about 650 species of nemertean worms in the world, 22 live in the Gulf of Mexico, and 16 live in the northern Gulf (near us).  They are basically marine, move across the environment on their slime trails, seeking prey primarily by the sense of smell at night.  Unlike the flukes and tapeworms, there are male and females in this group.  They fertilize their eggs externally to make the next generation of these harpooning hunters of the Gulf.

 

I don’t know if you will ever come across one of these.  You will know it by the flat body, pale color, and spade-shaped head, but I think it would be pretty neat to find one.  There are more worms to learn about in the Gulf of Mexico, but we will do that in another edition.

Share the Shore with Nesting Seabirds and Shorebirds!

Share the Shore with Nesting Seabirds and Shorebirds!

Black Skimmers foraging for fish. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

Black Skimmers and Least Terns, state listed species of seabirds, have returned along the coastal areas of the northern Gulf of Mexico! These colorful, dynamic birds are fun to watch, which can be done without disturbing the them.

Shorebirds foraging. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

Black Skimmer with a fish. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

What is the difference between a seabird and shorebird?

Among other behaviors, their foraging habits are the easiest way to distinguish between the two. The seabirds depend on the open water to forage on fish and small invertebrates. The shorebirds are the camouflaged birds that can found along the shore, using their specialized beaks to poke in the sandy areas to forage for invertebrates.

Both seabirds and shorebirds nest on our local beaches, spoil islands, and artificial habitats such as gravel rooftops. Many of these birds are listed as endangered or threatened species by state and federal agencies.

Juvenile Black Skimmer learning to forage. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

Adult black skimmers are easily identified by their long, black and orange bills, black  upper body and white underside. They are most active in the early morning and evening while feeding. You can watch them swoop and skim along the water at many locations along the Gulf Coast. Watch for their tell-tale skimming as they skim the surface of the water with their beaks open, foraging for small fish and invertebrates. The lower mandible (beak) is longer than the upper mandible, this adaptation allows these birds to be efficient at catching their prey.

Least Tern “dive bombing” a Black Skimmer that is too close to the Least Tern nest. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

Adult breeding least terns are much smaller birds with a white underside and a grey-upper body. Their bill is yellow, they have a white forehead and a black stripe across their eyes. Just above the tail feathers, there are two dark primary feathers that appear to look like a black tip at the back end of the bird. Terns feed by diving down to the water to grab their prey. They also use this “dive-bombing” technique to ward off predators, pets and humans from their nests, eggs and chicks.

Least Tern with chicks. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

Both Black Skimmers and Least Terns nest in colonies, which means they nest with many other birds. Black skimmers and Least Terns nest in sandy areas along the beach. They create a “scrape” in the sand. The birds lay their eggs in the shallow depression, the eggs blend into the beach sand and are very hard to see by humans and predators. In order to avoid disturbing the birds when they are sitting on their nests, known nesting areas are temporarily roped off by Audubon and/or Florida Fish and Wildlife Conservation Commission (FWC) representatives. This is done to protect the birds while they are nesting, caring for the babies and as the babies begin to learn to fly and forage for themselves.

Threats to these beautiful acrobats include loss of habitat, which means less space for the birds to rest, nest and forage. Disturbances from human caused activities such as:

  • walking through nesting grounds
  • allowing pets to run off-leash in nesting areas
  • feral cats and other predators
  • litter
  • driving on the beach
  • fireworks and other loud noises

Audubon and FWC rope-off nesting areas to protect the birds, their eggs and chicks. These nesting areas have signage asking visitors to stay out of nesting zones, so the chicks have a better chance of surviving. When a bird is disturbed off their nest, there is increased vulnerability to predators, heat and the parents may not return to the nest.

Black Skimmer feeding a chick. Photo Credit: Jan Trzepacz, Pelican Lane Arts.

To observe these birds, stay a safe distance away, zoom in with a telescope, phone, camera or binoculars, you may see a fluffy little chick! Let’s all work to give the birds some space.

Special thanks to Jan Trzepacz of Pelican Lane Arts for the use of these beautiful photos.

To learn about the Audubon Shorebird program on Navarre Beach, FL check out the Relax on Navarre Beach Facebook webinar presentation by Caroline Stahala, Audubon Western Florida Panhandle Shorebird Program Coordinator:

In some areas these birds nest close to the road. These areas have temporarily reduced speed limits, please drive the speed limit to avoid hitting a chick. If you are interested in receiving a “chick magnet” for your car, to show you support bird conservation, please send an email to: chrismv@ufl.edu, Please put “chick magnet” in the subject line. Please allow 2 weeks to receive your magnet in the mail. Limited quantities available.

Embrace the Gulf 2020 – flatworms

Embrace the Gulf 2020 – flatworms

Okay, this is a gamble.

I began this series to celebrate the year of the Gulf of Mexico – “Embracing the Gulf 2020”.  The idea was to write about the habitats, creatures, economic impacts, and issues surrounding the “pond” that we live on.  I did a few introductory articles and then jumped right into the animals.  We began with the fun ones – fish, sea turtles, whales – and now we are in the more unfamiliar – invertebrates like sponges and jellyfish.

 

But worms? Really? Who wants to read about worms?

A classic flatworm is this lung fluke.
Photo: Kansas State University.

Well, there are a lot of them, and they are everywhere.  You will find in many sediment samples that worms dominate.  They also play an important role in the marine community.  They are great scavengers, cleaning the environment, and an important source of food in the food chains of the more familiar animals.  But they are gross and creepy.  When we find worms, we think the environment is gross and creepy – and sometimes it is, remember they CLEAN THE ENVIRONMENT.  But worse is that many are parasites.  Yes… many of them are, and that is certainly gross and creepy.  Flukes, tapeworms, hookworms, leeches, who wants to learn amore about those?  Well, honestly, parasitism is an interesting way to find food and the story on how they do this is pretty interesting… and gross… and creepy.  Let’s get started.

 

According to Robert Barnes’ 1980 book Invertebrate Zoology, there are at least 11 phyla of worms – it is a big group.  We are not going to go over all of them, rather I will focus on what I call the “big three”: flatworms, roundworms, and segmented worms.  We will begin with the most primitive, the flatworms.

 

As the name implies, these worms are flat.  They are so because they are the last of what we call the “acoelomate” animals.  Acoelomates are animals that lack an internal body cavity and, thus, have no true body organs – there is no where for them to go.  So, they absorb what they need, and excrete, through special cells in their skin.  To be efficient at this, they are flat – this increases the surface area in contact with the environment.  There are three classes of flatworms – one free swimming, and two that are parasitic.

This colorful worm is a marine turbellarian.
Photo: University of Alberta

The free-swimming ones are called turbellarians.  Most are very small, look like leaves, very colorful, and undulate as they swim near the bottom. They have “eye-like” cells called photophores that allow them to see light – they can then choose whether to move towards the dark or not.  They have nerve cells but no true brain, and one only one opening to the digestive tract – that being the mouth, so they must eat and go to the bathroom through the same opening.  Weirder yet, the mouth is usually in the middle of the body, not at the head end.  Some are carnivorous feeding on small invertebrates, others prefer algae, others are scavengers (CLEANING THE OCEAN).  They can reproduce by regenerating their bodies but most use sexually reproduction.  They are hermaphrodites – being both male and female.  They can fertilize themselves but more often seek out another worm.  Fertilization is internal and they lay very few eggs.

The human liver fluke. One of the trematode flatworms that are parasitic.
Photo: University of Pennsylvania

The second group are called trematodes and they are the parasites we know as “flukes”.  We have heard of liver flukes in livestock and humans, but there are marine versions as well.  They have adhesive organs located at the near the mouth that help hold on, and a type of skin that protects them from their hosts’ defensive enzymes.  They feed on cells, mucous, and sometimes blood – yep… gross and creepy.  Some are attached outside of their hosts body (ectoparasites) others are attached to internal organs (endoparasites).  The ectoparasites breath using oxygen (aerobic), endoparasites are anaerobic.  Like their turbellarian cousins, they are hermaphroditic and use internal fertilization to produce eggs.  They differ though in that they produce 10,000 – 100,000 eggs!  Their primary host (the one they spend their adult life feeding on) is always a vertebrate, fish being the most common.  However, their life cycle requires the hatching larva find an intermediate host where they go through their developmental growth before returning to a primary host.  These intermediate host are usually invertebrates, like snails.  The eggs are released with the fish feces – a swimming larva is released – enters a snail – begins part of the developmental growth – consumed by an arthropod (like a crab) – completes development – and the crab is consumed by the fish – wah-la.  The adults are usually found in the gills/lungs, liver, or blood of the vertebrate hosts.  Gross and creepy.

The famous tapeworm.
Photo: University of Omaha.

Better yet are the tapeworms.  We have all heard of these.  They are also all parasites, but all are endoparasites.  Weirder, they do not have a digestive tract.  Gross and creepy.  Their heads are very tiny compared to their bodies and have either four sets of suckers, or hooks, to hold onto the digestive tract of their hosts (usually vertebrates).  The head is actually round but the body is very flat and divided into squares called proglottids.  Each proglottid gets larger as you move towards the tail and each possesses all of the reproductive material needed to produce new worms – they too are hermaphrodites. They also have a type of skin that protects them from the enzymes of their hosts.  They also require an intermediate host to complete their life cycle so the proglottids will exit the hosts body via feces and complete the cycle similar to the trematodes.

I began this with a comment on how worms benefit the overall marine environment of the Gulf.  It is hard to see that in these flatworms.  They are either just another consumer out there, or nasty parasites others in the community must deal with.  Well… we look at the roundworms next time and see what they have to offer.

 

Reference

Barnes, R. 1980. Invertebrate Zoology. Saunders College Press.  Philadelphia, PA. pp. 1089.

Embrace the Gulf 2020 – the jellyfish

Embrace the Gulf 2020 – the jellyfish

I’d like to be a jellyfish… cause jellyfish don’t pay rent…

They don’t walk and they don’t talk with some Euro-trash accent…

Their just simple protoplasm… clear as cellophane

They ride the winds of fortune… life without a brain

 

These lyrics from Jimmy Buffett’s song Mental Floss sort of sums it up doesn’t it.  The easy-going lifestyle of the jellyfish.

Everyone who visits the Gulf coast knows about these guys, but few people… very few… like them.  For most, the term jellyfish signals “pain”, “fear”, and “death”.  The purple flag is flying, and no one wants to enter the water.  Folks from the Midwest call local hotels and condos asking, “when are the jellyfish going to be there?”  It’s understandable.  Who wants to spend their week vacation on the Gulf inside a hotel because you can’t go swimming?

I found this along the shore last winter. These are cannonball jellyfish.

I would almost (…almost) rather be diving with a shark than hundreds of jellyfish.  When you spot them, they are everywhere.  Quietly swarming like ghosts.  You push them off and they appear to move towards you – almost like smoke from a campfire, you can’t get away.

 

They are creepy things.  But amazing too!

As Mr. Buffett’s points out, they are simple “protoplasm”.  Their body is primarily a jelly-like substance called mesoglea – and most of that is water.  If you place a dead jellyfish on your dock and come back that afternoon, you will probably find just a “stain” of where it was – there is almost nothing to them.

 

The “bell” of the jellyfish is mostly mesoglea.  Some jellyfish have thick layers of this, others much thinner.  Some have a small flap of skin along the margins of the bell called the velum which they can undulate and swim – but they are not strong swimmers.  If the tide is going out, swim as they may… their heading out also.

glowing jellyfish

The bell shaped body of a jellyfish with numerous tentacles.

Many species of jellyfish have interesting markings within the bell.  One has a white-colored structure that forms a 4-leaf clover.  Another has red triangles all connecting at the center of the bell.  For many, these structures are the ones that produce the gametes.  Jellyfish reproduce sexually but are hermaphroditic – meaning they produce female eggs and male sperm in the same animal.  There is no physical contact between animals, they just release the gametes into the ocean when they are in thick swarms and wah-la… new jellyfish – many new jellyfish.

 

On the bottom of the bell is a single opening that leads to a single pouch.  This opening is the mouth, and the pouch is called the gastrovascular cavity.  Jellyfish are predators – carnivores.  There are no teeth, and most do not seek their prey – their prey finds them.  Hanging from their bell are the tools of the killing trade, the part of this animal we do not like… the tentacles.  Some tentacles can extend for several feet beyond the bell, others you can hardly notice them – but this is where the killing happens.

 

Along the tentacles there are small capsules called cnidoblasts which contain small cells called nematocyst.  These nematocyst contain a coiled dart which at the end contains a drop of venom.  There is a trigger associated with this cell.  The jellyfish does not fire it – instead, the prey bumps the trigger and the nematocyst “fires”.  The drop of venom is injected, along with the hundreds of other nematocysts along the tentacle the fish just bumped.  This venom paralyzes the prey, other tentacles coil around it firing more nematocysts, and the tentacles retract towards the mouth – bingo… lunch.

This box jellyfish was found near NAS Pensacola in November of 2015.
Photo: Brad Peterman

Of course, the same happens when people bump into them.  For us it is painful and unpleasant – but we are not consumed.  That said, some species are quite painful.  Some will force people to the hospital, and some have even killed people.  The Box Jellyfish is the most notorious of these deadly ones.  Known for their habits in Australia, there are at least two species found in the Gulf.  The ones found here are not common, and there are no reported deaths, but they do exist.  The Four-Handed is the one more widespread here.  It actually has eyes, can detect predators and prey and swim towards or away from them, and the male fertilizes the female internally – not your typical jellyfish.

 

The more familiar painful one is the Portuguese Man-of-War.  This creature is more like a sponge in that it is not just one creature but a large “condo” of many.  Some cells are specialized in feeding, these are found on their long tentacles.  Others specialize in reproduction; these are found near the blue colored air bag.  They produce this blueish colored air bag which is exposed above the surface.  The wind pushes on the bag like a sail and this moves the creature across the environment in search of food.  Hanging from the bag are long tentacles which are made up of individuals whose stomachs are all connected.  So, when one group of cells makes contact and kills a prey – they consume it and the tissue is moved through the connecting stomachs to feed the whole colony.  To feed a whole colony, you need a big fish – to kill a big fish, you need a strong toxin, and they have it.  These are VERY painful and have put people in the hospital, some have died.  Some say that the Portuguese man-of-war is not a “true” jellyfish.  This is true in the sense that they belong to a different class of jellyfish.  There are three classes, the Scyphozoans being what we call the “true” jellyfish – Portuguese man-of-wars are not scyphozoans, but rather hydrozoans.

The colonial Portuguese man-of-war.
Photo: NOAA

Another interesting thing about jellyfish, is that they are all not jellyfish-like.  As we just mentioned, there are two other classes and one other phylum of jellyfish-like animals.  Hydrozoans and anthozoans are not your typical jellyfish.  Rather than being bell-shaped and drifting in the ocean looking for food, they are attached to the seafloor and look more like flowers.  Their tentacles are usually smaller but do contain nematocysts.  Their toxin can be strong, some do eat fish, but most have a weaker toxin and feed on very small creatures – some only eat plankton.  These would include the hydra, sea anemones, and the corals.  As mentioned above, this also would include the Portuguese man-of-war.

 

Comb jellies are those jellies that drift in the currents and have no tentacles.  We commonly collect them and toss them at each other.  When I was growing up, we referred to them as “football jellies” because of this.  The reason they do not sting is not because they do not have tentacles (some species do) but rather they do not have nematocyst and cannot.  Rather they have special cells called colloblast that produce a drop of sticky glue at the end which they use to capture prey.  Not having toxins, they cannot kill large prey but rather feed on smaller creatures like plankton and each other – they are cannibals.  For this reason, they are in a whole different phylum.

The nonvenmous comb jelly.
Photo: Bryan Fluech

 

 

The jellyfish of the Gulf are a nuisance at times but are actually amazing creatures.