The word “jellyfish” tends to initiate a similar response in most people – “scream”, “run”, “this is going to hurt”. Being stung by a jellyfish is not pleasant and is something most would prefer to avoid. Our beaches warn us when they are out by flying a purple flag.
When exploring the seagrasses, this is not the first animal people thing they will encounter. Few associate jellyfish with the seagrass community. But within any community there are those we call residents (they reside here) and those we call transients (just passing through). It is the second group that we can place most jellyfish, at least the ones we are concerned about.
The sea nettle.
Photo: University of California at Berkley.
Jellyfish are animals, but not your typical ones. They are obviously invertebrates but differ from most others by having radial symmetry (having a distinct top and bottom, but no head nor tail). They possess ectoderm and endoderm (so, they have a skin layer and some internal organs) but they lack the mesoderm that generates systems such as the skeletal, circulatory, and endocrine. Though they do not have a brain, they do have a simple nervous system made up of basic neurons and some packets of nerve cells called ganglia. They seem to know when they are not in the upright position and know when they have stung something – which initiates the feeding behavior. But they are pretty basic creatures.
When you view a jellyfish the first thing you see is the “bell” and the tentacles – we always see the tentacles. The bell is usually round (radial), could be bell-shaped, or could be flat. It is made of a flexible plastic-like jelly material called mesoglea. Most of the mesoglea is actually water. When you place most jellyfish on the dock and come back in a few hours there may be nothing but a “stain” of where it was. It completely evaporated. There are some exceptions to this, like the moon jelly and the cannonball jelly, who leave thick masses of mesoglea for long periods of time.
Image: Wikipedia.
If you look closer at the “bell” you will see shapes within the mesoglea. Some are stripes, and may have color to them, others look like a clover leaf. These are the gonads of the animal. Jellyfish are hermaphroditic (the gonads can produce both sperm and egg), and they reproduce by releasing their gametes into the water column when triggered by some environmental clue to do so.
Around the edge of the “bell” many have a thin piece of tissue called the velum that can undulate back and forth and allow the jellyfish to swim. Swimming can involve moving up or down in the water column, or turning around, but the swimming action is not very strong and the tide and current actually plays a larger role in where the animals go – like pushing them through a seagrass bed.
Under the “bell” is a single opening, the mouth, that leads into a simple gut (the gastrovascular cavity). This serves as the stomach of the creature. But there is no anus, when the jellyfish has digested its food, the waste is expelled through the same opening – the mouth. This is called an incomplete digestive system.
Jellyfish are predators and hunt small creatures such as baitfish. Though they know whether they are upside down or not, and may be able to detect light, most have no true eyes and cannot see their prey. Some species may be able to detect scent in the water and undulate their velum to try and move towards potential food, but most drift in the water and hope the tide carries them to dinner. To kill their prey, they extend tentacles into the water. These tentacles are armed with stinging cells known as nematocysts. Each nematocyst holds a coiled harpoon with a drop of venom at the tip. They are encased in a cell membrane and are triggered when an object, hopefully food, bumps an external trigger hair that will fire the harpoon. This will then trigger the release of many nematocysts and the potential prey will be “stung” by many drops of venom. The venom can either kill or paralyze the prey at which time the tentacles bring it to the mouth. Many jellyfish have venom that is painful to humans, like the sea nettle and moon jelly, others have a mild venom that we do not even notice. Some have a very strong venom and can be quite painful, like the Portuguese man-of-war which has put some in the hospital. The famous box jelly of Australia has actually killed humans. We do have box jellies in the Gulf of Mexico, but they are not the same species.
This box jellyfish was found near NAS Pensacola in November of 2015.
Photo: Brad Peterman
As the tide pushes these transients through the seagrass meadows, their tentacles are extended and small baitfish like juvenile pinfish, croakers, and snapper become prey. But there are resident jellyfish as well.
With the Phylum Cnidaria (the stinging jellyfish) there are three classes. Class Scyphozoa includes the bell-like jellyfish that drift in the water column with extended tentacles – what are referred to as medusa jellyfish. But there are two other classes that include benthic (bottom dwelling) jellyfish called polyps.
Polyp jellyfish resemble flowers. The “bell” part is a stalk that is stuck to a rock, pier, or seagrass blade. Their tentacles extend upwards into the water column giving the creature the look of a flower. Instead of drifting and dragging their tentacles, they hope to attract prey by looking like a hiding place or other habitat. The sea anemone is a famous one, and a good example of the polyp form. But it also includes corals and small polyps known as Hydra. Hydra are tiny polyps that are usually colorless and can easily attach to a blade of turtle grass. Here they extend their tentacles into the water column trying to paralyze small invertebrates that are swimming by or grazing on the epiphytes found on the grass blades.
The polyp known as Hydra.
Photo: Harvard University.
Another jellyfish that drifts in the current is Beroe, what some call the “football jellyfish” or “sea walnut”. This a relatively small blob of jelly that lacks tentacles but rather has eight rows of cilia/hair (ctenes) along its side that move quickly and move this animal through the water. But like their medusa cousins, not against the tide or current. These jellyfish do not sting, they lack nematocysts, and hence are in a different phylum known as Ctenophora. Kids often find and play with them when they are present, and they are luminescent at night. These stingless jellyfish feed on small plankton and each other and are another transient in the seagrass community.
The non stinging comb jelly.
Florida Sea Grant
There are certainly species of jellyfish to be aware of and avoid. But as you look deeper into this group there are harmless and fascinating members as well. Most of these Hydra are very small and hard to see while snorkeling, but they are there. Another creature to try and find while you are exploring and play “seagrass species bingo”. Have fun and stay safe.
The open grasslands of the American west support huge herds of grazing herbivores such as bison, antelope, and deer. These large herds again support populations of hunters such as wolves, coyotes, and – historically – bears. The huge acres of wetland grasses we call marshes are productive as well, with all sorts of grazing creatures that feed on the grass like snails and insects, which in turn support populations of first order carnivores like birds, crabs, and turtles, who then feed larger predators like alligators, otters, and raccoons.
The salt marsh is full of life, if you look close enough. Photo: Rick O’Connor
One would think that the submerged seagrass meadows would work in the same way. But there are no large herds of bison like creatures that graze on the grasses. True, manatees and sea turtles do graze on these, but not in the numbers we see with bison and antelope. There are numerous species of snails and crustaceans that live in seagrass, but it is not the grass they are interested in… it is the epibiota. These epibiota are the key to vast diversity of creatures living in seagrasses. If you snorkel or seine through a submerged grassbed you will notice the majority of creatures are small. This place is a nursery for the estuarine and marine environments. These grasses provide excellent hiding places and the epibiota provide the food they need to grow.
Grassbeds are also full of life, albeit small creatures.
Photo: Virginia Sea Grant
So, what are these epibiota?
The term epibiota means “creatures that live on other creatures”. They can be further broken down into epiphytes (plants that growth on other creatures), and epizoids (animals that grow on other creatures). Spanish moss is a familiar example of an epiphyte most people know. Barnacles growing on a turtle shell, or a whale could be an epizoid you are familiar with. Many epibiota are small, even microscopic. You can see the algae growing on the shells of turtles, or the fur of the sloth. There are also numerous epizoids that are microscopic, and no one sees. It is a whole field of microbiology – the study of the natural history and diversity of this tiny world that, certainly in the case of seagrasses, makes the whole thing work.
The wide blades of turtle grass provide habitat for a variety of epibiota.
Photo: UF IFAS
With the seagrasses you will not always see the epibiota we are talking about. At times, there are mats of algae growing on the grass like Spanish moss on oak trees. We typically see these epibiotic macroalgae growing on seagrasses in the spring and summer. Most of these algal mats are red algae. Studies have shown that they support juvenile animals as hiding habitat and can increase the overall biomass of seagrass meadows. But, like with all things, too much of a good thing can have a negative effect on seagrass meadows as well. The seaweed can smother the grasses, reducing needed sunlight, and enhance the decline of seagrasses in some areas.
Gracilaria is a common epiphytic red algae growing in our seagrass beds. Photo: Rick O’Connor
Most of the epibiota feeding the growing populations of shellfish and finfish using these nurseries are microscopic plants and animals that appear to us as “scum” on the blades of the grass. As you might expect, the wider the blade (in this case turtle grass) can support a higher diversity and abundance of growing grazers than the thinner shoal grass.
A study conducted in 1964 listed 113 species of microscopic algae existing on the blades of seagrasses in Florida. They include such creatures as diatoms, cynobacteria, and bryozoans. We will focus on these.
Diatoms are quite abundant on seagrass blades and provide for microscopic grazers.
Photo: University of New Hampshire
Diatoms are single celled plant-like algae that are encased in a clear silica shell. They are one of the most abundant forms of oxygen producing plant-like creatures found in the sea. Many species drift with the phytoplankton layers of the open ocean. Others are benthic, living on the bottom upon rocks, seawalls, turtle shells, and seagrasses. It has been stated that 50% of the oxygen produced on our plant comes from the diatoms and the dinoflagellates (another microscopic plankton).
Cells of a species of cyanobacteria.
Photo: Florida Atlantic University.
Cyanobacteria are what many call blue-green algae. They produce a darker colored green with their photosynthetic pigments – thus the name blue-green algae – but were not initially identified as a bacteria – which they are now because they lack an organized nucleus. Many have heard of the recent cyanobacteria blooms in central and south Florida in freshwater systems. Some species are toxic and have caused fish kills and even made pets, who drank from water with cynaobacteria, very sick. There hundreds of different species found in marine systems. Like diatoms, some live in the water column, others are attached to an object on the bottom – like seagrasses.
This beautiful matrix was built by a group of microscopic animals known as bryozoans.
Bryozoans are microscopic colonial animals. They act and behave similar to corals, though they are much smaller. Some species appear as a “cast net” over the shell of a snail or clam, and can be seen on blades of turtle grass as well. There are many other species of these colonial creatures that call seagrass home.
We are highlighting these three groups but there are many other forms of epiphytes and epizoids growing on these grass blades. And it is these that the small grazers, like tiny crustaceans, feed upon, which in turn are what the millions of small silver juvenile finfish and crabs are feeding on. The seagrass meadow biodiversity and productivity is dependent on them and most Panhandle folks do not know they are there. Dr. Edward O. Wilson made a comment in his book Half Earth, that we have been focused on conservation of wildlife and habitat for many years now – but we fully do not understand what it is we are trying to conserve. We focus on blue crab and manatee conservation and do not realize that conservation of these micro-communities is essential for conservation, or restoration, success. The first step in conserving such communities is knowing they exist and how they support the system. You now have a little more knowledge of them, but there is SO much more to learn.
It sounds like one of those Sci-Fi thrillers where there is a giant asteroid heading to Earth and we need a special team led by Bruce Willis to save the planet. But in this case it is not a large rock, but a large mass of seaweed. And the threat is not a huge impact that would form tidal waves and atmospheric black out but large masses of seaweed covering the beaches up to a foot or more. Once on the beach, the mass of seaweed would begin to break down releasing odors and attracting insects that would not be popular with tourists – just as we get into the peak of tourist season around the state.
Mats of Sargassum on a south Florida Beach.
Photo: University of Florida
It is not something new, this has been a problem in south Florida for a few years now, but this year scientists can see the massive blob of seaweed heading this way and it is larger than before. They are expecting some beaches in Florida to be heavily impacted.
The seaweed in this floating mass is a brown algae known as Sargassum (Gulfweed). Like many brown algae’s, it is yellowish-brown in color and possesses small air bladders called pneumatocysts. These pneumatocysts allow large brown algae, like kelp, to stand tall like a tree in the water column – or, like Sargassum, to float on the surface where they can reach the much-needed sunlight.
Sargassum has small air bladders called pneumatocysts to help them remain afloat on the surface.
Photo: Florida Sea Grant
There are two species of Sargassum that are found in the South Atlantic: Sargassum natans and S. fluitans. They are not easily distinguished so most just say “sargassum”. These seaweeds form large floating mats that drift in the ocean currents. The clockwise rotation of the North Atlantic gyre creates a central point around which the currents spin that is calm – similar to the eye of a hurricane. Here, the sargassum collects in large masses and was noted in the logs of Christopher Columbus as the “Sargasso Sea” – a place to avoid for colonial sailors due to the fact there is little wind or current here.
The Sargasso Sea
Image: University of Florida
Mats of this algae creates an ecosystem drifting across the sea housing transient and residential species that have been the study of marine biologists for decades. The seaweed will get caught in currents that bring it close to shore where fishermen seek it out fishing for jacks or mahi-mahi. Baby sea turtles will use it as refuge until they are large enough to return to the shores of the continents and islands. It will at times get caught in currents that bring it ashore where beach combers sift through to see what they can find. As we mentioned, once on dry ground the seaweed begins to die releasing the odors of decaying sea life and attracting an assortment of insects. When this happens coastal communities will use tractors to drag and remove the smelly mats and deposit them in the local landfill.
In recent years, in south Florida, the amount of this seaweed has increased. The seaweed has formed large mounds on the beaches making beach combing an ordeal and the smell unbearable in many communities. Some of the Sargassum finds its way into the canals of the Florida Keys where it sits and decays, decreasing dissolved oxygen and causing a decline in abundance of some local marine communities. They have responded by removing the Sargassum to the local landfill but are experimenting with composting the material for fertilizing other plants.
Several researchers have experimented with the composting idea with some encouraging results. Some have found a use for it as mulch for coastal mangrove shoots that have lost much of their natural fertilizers due to coastal urbanization. There are problems with using this in some plant settings. 1) It could be too salty for some landscape plants. 2) There is the concern of the amount of arsenic present. Studies continue.
The recent large masses of Sargassum coming ashore began in 2011. What is causing this recent increase in Sargassum on the beaches? Researchers are finding the source of this material is not mats rotating off of the Sargasso Sea but forming in the belt of moving water between the North Equatorial Current in the south Atlantic and the equator itself. The exact cause of this increase growth is uncertain but could be linked to an increase of nutrients from regional rivers, like the Amazon, and from increased ocean temperatures due to climate change – both of these are exactly what seaweeds like.
This year the mass of seaweed seen from satellites is particularly large – over 5,000 miles. It is drifting in the currents heading for the Caribbean and Florida. It will most likely impact south Florida, but researchers do not believe the impact will be as large along Florida panhandle beaches. They will continue to monitor and report on the movement of this mass of seaweed over the course of the summer.
Spring break is upon us and this often includes trips to the beach. Encountering dolphins and other marine life in the wild can be a once-in-a lifetime experience. There are a few simple guidelines that you can follow to prevent human/wildlife conflict while promoting a positive and memorable experience. These tips from NOAA National Marine Sanctuaries can serve as a guide to recreating responsibly.
Keep my pets home or on a leash: Before you take your pet on an outdoor adventure, make sure they are permitted to be there, and if they are, keep them on a leash at all times! When pets get too close to wildlife, especially marine mammals, all animals are at risk of harm, stress, and even disease.
Lead by example: What are some ways you can lead by example while enjoying the outdoors? By helping others to become responsible wildlife watchers, we protect both people and animals. Show respect for wildlife and other visitors, speak up about wildlife viewing violations, and choose businesses who recreate responsibly.
Report wildlife that seems sick or abandoned: Plenty of marine animals love to spend time on the beach to rest or eat, just like us! Seeing wildlife on the shore is not always cause for concern, but if you see an animal that appears sick or abandoned, make sure to give it plenty of space and contact your local wildlife authorities. Contact the FWC’s Wildlife Alert Hotline at 1-888-404-3922 in Florida.
Keep snacks to yourself: Sharing is caring, but not when it comes to sharing food with animals! Wildlife are perfectly capable of finding their own food. Feeding wildlife often does more harm than good and is actually illegal for many species, so keep those snacks to yourself!
Lend a hand with trash removal: Each year, billions of pounds of waste enter our ocean. This debris can be ingested by wildlife causing them harm or even death. To do your part try reusing and even refusing plastics. Make sure to properly dispose of your garbage and recycle whenever possible as well pick up any debris you see!
Keep my hands to myself: You might be tempted to pet a seal basking in the sun but getting too close or startling them can evoke aggressive behavior and seriously injure them as well as you. Be sure to stand at a safe distance to get that perfect photo as touching, feeding, or harassing wild animals is often illegal and can ruin both yours and the animals’ day.
Hang back and enjoy the view: Giving wildlife their space is SO important! Getting too close to wildlife exerts the precious energy they rely on for hunting, attracting mates, and raising their young. By hanging back from our wildlife, we can help to keep them healthy and stress-free.
Finally, we encourage the public to show their support for wildlife on social media by taking the pledge and share this information with a friend. https://go.usa.gov/xH385.
¿Está interesado en hacer algo que beneficie a su comunidad marina local? ¡Disfruta de días al sol, como un “Scallop Sitter” (cuidador de las vieiras)!
“Scallop Sitters” (cuidador de vieiras) es uno de nuestros programas de voluntariado cooperativo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés). Históricamente, las poblaciones de vieiras de la bahía eran muy numerosas y podían sustentar las pesquerías en muchas bahías del norte de Florida, incluidas la bahía de San Andrés, la bahía de San Juan y el Puerto de los Caimanes (Condado de Franklin). Años consecutivos de malas condiciones ambientales, pérdida de hábitat y “mala suerte” en general resultaron en una escasa producción anual y provocaron el cierre de la pesquería de vieiras. La vieira de la bahía es una especie de corta vida que pasa de ser una cría a adultos que desovan y muere en un año aproximadamente. Las poblaciones de vieiras pueden recuperarse rápidamente cuando las condiciones de crecimiento son buenas y pueden disminuir drásticamente cuando las condiciones de crecimiento son malas.
En 2011 se presentó la oportunidad de poner en marcha la restauración de las vieiras de la bahía del norte de Florida. Con la financiación del derrame de petróleo de Deepwater Horizon, se propuso un programa de restauración de vieiras en varios condados, que finalmente se estableció en 2016. Los científicos de Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) utilizan vieiras criadas en criaderos, obtenidos a partir de progenitores o reproductores de las bahías locales, para cultivarlas en masa y aumentar el número de adultos reproductores cerca del hábitat crítico de las praderas marinas.
La Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) también creó otro programa en el que los voluntarios pueden ayudar con la restauración llamado “Scallop Sitters” en 2018 e invitó a UF/IFAS Extension a ayudar a dirigir la parte de voluntarios del programa en 2019, lo que llevó a esfuerzos específicos en los condados del Golfo y la Bahía.
Para ayudar a las vieiras, los “Scallop Sitters” trabajan con UF/IFAS Extension, Florida Sea Grant y los científicos de restauración de la Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) limpiando las vieiras y comprobando la salinidad una vez al mes desde junio hasta enero. Foto de Tyler Jones, UF/IFAS Extension y Florida Sea Grant.
Después del hiato de 2020 debido a COVID-19, el programa presumió de casi 100 voluntarios para la campaña de 2021. UF/IFAS Extension se asocia de nuevo con Pesca y Vida Silvestre de Florida (FWC, por sus siglas en inglés) en los Condados de Bahía y Golfo y Franklin. A pesar de los retos que suponen las lluvias, la escorrentía de las aguas pluviales y la baja salinidad, nuestros voluntarios de Scallop Sitter han proporcionado información valiosa a los investigadores y a los esfuerzos de restauración, especialmente en estos primeros años de nuestro programa. Los “Scallop Sitters” recogen información útil sobre la salinidad en las bahías de destino. Pero la mayor parte del impacto se produce al observar de cerca sus vieiras. Las vieiras que mantienen sus cuidadores tienen más posibilidades de desovar con éxito cuando sea el momento adecuado.
Una jaula “Scallop Sitter” lista para ser colocada cerca de las praderas marinas. Las jaulas son herramientas de restauración utilizadas para producir crías de vieira durante el ciclo anual de crecimiento. Foto de L. Scott Jackson.
¿Qué hace un cuidador de vieiras? Los voluntarios dirigen jaulas de exclusión de depredadores de vieiras, que quedan colocadas en la bahía o junto a un muelle. Los “Scallop Sitters” (cuidador de vieiras) vigilan la tasa de mortalidad y recogen datos sobre la salinidad que ayudan a determinar los objetivos de restauración y el éxito en las zonas seleccionadas.
¡Está invitado! ¡Cómo convertirse un “Scallop Sitter” (cuidador de vieiras)!
Las fechas de entrenamiento para 2023 se anunciarán en breve. Por favor, envíenos un correo electrónico si está interesado en ser voluntario o en recibir información adicional. Chantille Gooding, Coordinadora de Recursos Costeros del Condado de la Bahía. c.gooding@ufl.edu
Una institución con igualdad de oportunidades. UF/IFAS Extension, Universidad de Florida, Instituto de Ciencias Alimentarias y Agrícolas, Andra Johnson, Decana de UF/IFAS Extension. Las copias individuales de las publicaciones de UF/IFAS Extension (excluyendo las publicaciones de 4-H y de los jóvenes) están disponibles gratuitamente para los residentes de Florida en las oficinas de UF/IFAS Extension del condado.
I recent took my granddaughter on a dolphin tour out of Pensacola Beach. It was amazing. It was a cool October morning, not a cloud in the sky, the winds were calm, the water crystal clear due to the lack of rain over the past few weeks, and the dolphins were out.
They are amazing animals and always seem to grab your attention no matter how many times you see them. I was a student at Dauphin Island Sea Lab from 1980-81 and taught there from 1985-1990. No matter how many times we heard “dolphins” when out on one of the research vessels, everyone had to run over to look. People do enjoy seeing dolphins. There is just something about them.
A group of small dolphin leap from the ocean.
Photo: NOAA
During the tour at one location, we saw a group of them (a pod) feeding on fish in the shallow water. They would roll and chase, you could see the sand being kicked up from the bottom as they did. At another location we saw them in breeding mode. Slower moving, caressing, fluke slapping as they turned all around in the water near us. The tour guide told us all sorts of dolphin facts, and some great jokes to go along with them. It was a good program, and my granddaughter was loving it.
She looked over at me at one point and said, “dolphins use to walk on land”. I responded that actually their ancestors did. Dolphins, as we know them, were very much aquatic animals. This led to thoughts on other dolphin questions I have heard over the years.
What is the difference between a dolphin and a whale?
Size… and in some cases teeth.
All whales and dolphins are in the mammalian order Cetacea. Mammalian orders are divided based on the type of teeth they have. Cetaceans are homodonts, meaning they have only one type of tooth. For the toothed whales, these are canines, they lack the molars and incisors that many other mammals have. But some have no teeth rather a specialized fibrous material called baleen, similar to the bristles of a broom, with which they can filter plankton from the water.
There are over 90 species of cetaceans in the world’s oceans, 21 of those are known from the Gulf of Mexico. In a recent published survey by the National Marine Fisheries Service, most of the cetaceans in the Gulf of Mexico are of the toothed whale variety and most occur beyond the continental shelf (which is between 60 and 140 miles south of Pensacola). The only baleen whale in their report was the Byrde’s Whale (Balanopatera edeni). They estimate about 33 of these whales based on their transect surveys and all of these were found beyond the continental shelf between Pensacola and Apalachicola Florida. The largest of the toothed whales reported was the sperm whale, which can reach over 60 feet. They estimate 763 sperm whale in the Gulf, and they were found across the basin beyond the continental shelf.
But it is the bottlenose dolphin (Tursiops truncatus) that we see on the dolphin tours. This is a relatively small toothed whale, reaching lengths of 13 feet, though most in the Gulf region are less than 10 feet. They are the most abundant and most frequently encountered cetacean near shore and within the estuaries and seem to prefer these shallower waters to the open Gulf beyond the shelf. The National Marine Fisheries Service divides them into stocks based on their geographic distribution. They report 37 different stocks of bottlenose dolphins in the northern Gulf. These are divided into western, eastern, and northern stocks, and then subdivided into estuarine stocks. There are separate stocks for the Perdido Bay and Pensacola Bay groups. This report indicated the stock size for the Pensacola and Perdido Bay dolphins was unknown, though our tour guide indicated there were about 250 in the Pensacola Bay stock. The National Marine Fisheries Service did report about 179 dolphins in the Choctawhatchee Bay stock. The reports estimated over 51,000 individuals for the northern Gulf.
Though not listed as endangered or threatened by the Endangered Species Act, there is some concern on the smaller estuarine stocks and so they have been labeled as “strategic”. There has been fishery related mortality with these dolphins in our waters, primarily with longlining and otter trawl operations, but losses are less than four animals/year and do not seem to be impacting their populations.
What is the difference between a dolphin and a porpoise?
Though many associate the long beak as a dolphin, there are dolphins with short snouts. Killer whales are actually large dolphins. The answer goes back to the teeth, as it always does when classifying mammals. Dolphins have conical shaped teeth where porpoise have more spade shaped ones.
How smart are dolphins?
As everyone knows these are highly intelligent animals. They use an audible form of communication that includes squeaks, clicks, and whistles, to keep the pod together. Researchers have discovered that these audible sounds have a sort of “accent” to them that tells dolphins which pod the dolphin communicating is from. This appears to be very important being that dolphins from one social pod may not accept others from different one. I remember in 1993 when a group of five pantropical spotted dolphins stranded on Pensacola Beach. There were four adults and one 3-month year old in the group. After failed attempts to return the dolphins back to the Gulf, it was decided to transport them to a quarantine area near the EPA lab on Pensacola Beach. There was a virus spreading through some European populations and they did not want to risk taking them to the Gulfarium. In route three of the four adults passed away. The remaining adult was named Mango and the juvenile was named Kiwi. After a period of time in quarantine Mango passed away leaving on the young Kiwi. There was a move to return Kiwi to the wild but some of the dolphin experts on scene told me the likely hood of a different pod accepting Kiwi was a risk, and finding her original pod was very unlikely. After determining the dolphin did not have the virus of concern, they decided to move her to the Gulfarium in Ft. Walton Beach, where she lived the rest of her life.
How does dolphin echolocation work?
Echolocation is different than communication, in that it is inaudible. As with communication, the sounds are produced by expelling air through the blowhole. In the case of communication, there is a muscle that partially closes the opening of the blowhole producing the sounds we hear. In echolocation this is completely closed, and the sound waves are moved through a fat filled melon near the head. The shape and density of the melon can be changed by the animal to produce different frequencies of sound but all inaudible to our ears. These sounds are emitted through the melon into the environment, where they contact something and “echo” back to the dolphin. These echoes are received in a fat filled cavity of the lower jaw and transferred to the brain – where the animal is then made aware of the object out in front of them. Some studies suggest that it may be more than knowing there is an object, they may be able to distinguish different kinds of fish. Though it is most effective within 600 feet, studies show their range may be up to 2000 feet. Studies have also shown that some species of toothed whales can alter the frequency of these echolocated sounds to stun their prey making them easier to catch.
Dolphins are amazing animals.
They live between 30 and 50 years in the wild. During this time, they form tight social groups, feed on a variety of prey, and produce new members every 2-3 years. There is so much more to the biology, ecology, and social life of these animals and we recommend you read more. Once you understand them better, we also recommend you take a dolphin tour to view these amazing creatures.
