by Laura Tiu | Mar 11, 2022
World Wildlife Day was celebrated on March 3, 2022. This year’s theme is “Recovering key species for ecosystem restoration.” We celebrate this day to bring attention and awareness to many of the plants and animals that are considered threatened and endangered species and highlight efforts to conserve them. It is estimated that over a million species are currently threatened with extinction.
Turkey Creek Niceville, FL (credit E. Zambello)
Florida is considered a very biodiverse state having a great variety ecosystems and unique plants and animals that inhabit these areas. This makes Florida an attractive place to live but can result in increased pollution and land use changes that can be threats to this biodiversity. One local species that experienced this type of pressure is the Okaloosa darter. This tiny 1 to 2 inch fish dwindled to as few as 1,500 individuals surviving when it was declared endangered in 1973. Factors such as its small range, competition from other species, and historical land use practices including artificial impoundments, erosion, and siltation, contributed to its demise.
The Okaloosa darter prefers to live in small, clear, lightly vegetated streams fed by ground water seepage from sand hill areas. This highly specialized habitat is found in only six streams in Okaloosa and Walton Counties and almost exclusively within Eglin Air Force Base’s boundaries. Environmental managers from Eglin Air Force Base partnered with U.S. Fish and Wildlife Service and other agencies and worked diligently to reduce land use impacts and rehab the impaired streams over the past several decades. They reclaimed clay pits near stream headwaters, improved road crossings to reduce sedimentation and enhanced the habitat for the darter.
Okaloosa darter photo credit: FWS.gov
Due to these efforts, the population of Okaloosa Darters has increased to more than 600,000 and the species has now been down listed from endangered to threatened. In fact, the projects have been so successful that the darter is now being considered for delisting as a threatened and endangered species under the Endangered Species Act. This is something to celebrate on this World Wildlife Day as an example of how we can recover key species for ecosystem restoration. The best news is that Eglin Air Force Base’s Jackson Guard Unit is continuing to make on-base conservation a priority, not only for the Okaloosa Darter, but for other plants and animals under their purview.
by Rick O'Connor | Mar 11, 2022
Snook… Wait did you say Snook in the Florida panhandle?
Yep… they are not common, but they have seen here.
For those who do not know the fish and do not understand why seeing them is strange, this is a more tropical species associated with tarpon. In the early years of tourism in Florida tarpon fishing was one of the main reasons people came. Though bonefish and snook fishing were not has popular as tarpon, they were good alternatives and today snook fishing is popular in central and south Florida… but not in the north.
This snook was captured near Cedar Key. These tropical fish are becoming more common in the northern Gulf of Mexico.
Photo: UF IFAS
This fish is extremely sensitive to cold water, not liking anything under 60° F. They frequent the same habitats as tarpon, mangroves and marshes. They are euryhaline (having a wide tolerance for salinity) and can be found in freshwater rivers and springs. Actually, near river mouths is a place they frequent. The younger fish are more often found within the estuaries and adults have been found in the Gulf of Mexico. Again, this is a more tropical fish with records in Florida north of Tampa being rare. In the western Gulf the story is the same, almost all records are south of Galveston, Texas. Until recently…
Hoese and Moore1 cite a paper by Baughman (1943) that indicated the range of the fish had actually moved further south. One reason given was the loss of the much-needed salt marsh and mangrove habitats from human development. But in recent years there have more reports north of Tampa. Purtlebaugh (et al.)2 published a paper in 2020 indicating an increase in snook captured in the Cedar Key area of the Big Bend beginning in 2007. At first records only included adults, and the thought was these were “wayward” drifters in the region. But by 2018 they were capturing fish in all size classes and there was evidence of breeding going in the area. The range of the fish seemed to be moving north. The study suggests they still need warm water locations to over winter, and, like the manatees, springs seem to be working fine. But another piece of the explanation has been the reduction of hard freezes during winter in this part of the Gulf. Climate change may be playing a role here as well.
There seems to be other tropical species dispersing northward in a process some call “tropicalization” including the mangroves. There have been anecdotal reports of snook near Apalachicola where mangroves are becoming more common, and I know of two that were caught in Mobile Bay. There are mangroves growing on the Mississippi barrier islands as well. While explaining this during a presentation I was doing for a local group, a gentleman showed me a photo of a snook on his phone. I asked if he caught it in the Pensacola area. He replied yes. When I asked where, he just smiled… 😊 He was not going to share that. Cool.
There is no evidence that snook have established breeding populations are in our waters. Especially after this winter with multiple days with temperatures in the 30s, it is unlikely snook would be found here. But it is still interesting, and we encourage anyone who does catch one, to report it to us.
References
1 Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press. College Station Tx. Pp 327.
2 Purtlebaugh CH, Martin CW, Allen MS (2020) Poleward expansion of common snook Centropomus undecimalis in the northeastern Gulf of Mexico and future research needs. PLoS ONE 15(6): e0234083. https://doi.org/10.1371/journal.pone.0234083.
by Rick O'Connor | Feb 18, 2022
I recently posted an article about the seahorses of the Florida panhandle. It would be remiss of me if I did not include their close cousins the pipefish. Where seahorses are well known but hard to find, pipefish are easy to find but not well known.
The seahorse-like pipefish.
Photo: University of Florida
Pipefish are in the same family as seahorses, Syngnathidae, and are basically elongated seahorses. Pulling seine nets in local grassbeds we often catch them. Students always ask what they are. “Are these needlefish?” is a frequent question. I reply “no, they are pipefish”. Which then comes “pikefish?”. To which I reply “No, PIPEfish… like P-I-P-E… – they are basically elongated seahorses”. And then there is always – “coool”. To which I reply “yes… very cool”.
Pipefish have the same body armor, body rings, and long tube snout of the seahorse. However, they lack the curled prehensile tail for a more elongated body, looking more a grass blade than their cousins. They actually have a caudal fin (the fin most call “fish tail”). Most range between 3-6 inches long but the chain pipefish can reach a length of 10 inches, this is the “big boy” of the group. Like seahorses, they hide in the grass using their tube-shaped mouths to suck in small planktonic food. Like the seahorses, the males’ possess a brood pouch to carry the fertilized eggs and give live birth (ovoviviparous).
The pipefish can quickly be divided into two groups – those with long snouts, and those with short – and this can be easily seen when captured in a net. After that identification gets a bit tricky, you have to count rays in the fins or rings on the body. It is sufficed to say, “it’s a pipefish” and leave it at that.
Those with long snouts include the Opossum, Chain, Dusky, and Sargassum pipefish.
The Opossum Pipefish (Microphis brachyurus) is about 3 inches long and was not reported from the northwestern Gulf of Mexico according to Hoese and Moore1. In the eastern Gulf, our way, it is considered rare but has been found in salt marshes, seagrasses, and in Sargassum mats drifting in from the Gulf. The Florida Museum of Natural History list this fish as a “marine invader”2. In 1991 NOAA listed it as a species of concern due to its decline across the region3. There are reports of this pipefish entering freshwater creeks within our estuaries.
The Chain Pipefish (Syngnathus louisianae) has a very long snout and is the “big boy” of the group reaching 10 inches in length. It is quite common along the panhandle and has one of the larger ranges of this group, found all along the Atlantic coast, throughout the Gulf of Mexico and in the Caribbean.
The Dusky Pipefish (Syngnathus floridae) is a long-snout, large pipefish reaching a length of eight inches. It prefers higher salinity than many pipefish and is found throughout the Gulf of Mexico and along the Atlantic seaboard often offshore.
The Sargassum Pipefish (Syngnathus pelagicus). This is a good scientific name for this fish (pelagicus) for it lives on the large mats of Sargassum weed that drifts across the oceans. Because of this it has a worldwide distribution. This longnose pipefish reaches the typical length of six inches. It lives as many other pipefish do hiding in the grass snapping up food when it comes close enough but it’s habitat is often drifting offshore and inshore sightings of this species are rare.
There are three species of “short-snout” pipefish.
The Fringed Pipefish (Anarchopterus crinigerus) is a smaller pipefish reaching only three inches. It seems to be absent in the western Gulf but is found along the Florida panhandle, the Gulf coast of peninsula Florida, and through the Caribbean to Brazil.
The Northern Pipefish (Syngnathus fuscus) reaches a length of six inches. It is very common along the Atlantic seaboard but Hoese and Moore1 report only four specimens from the Gulf of Mexico. This one would be considered very rare, and an expert should identify it if one thinks they have it.
The Gulf Pipefish (Syngnathus scovelli) is one of the more common pipefish collected in our waters. It is a short-snout species reaching the typical six inches but has these distinct bluish-gray bars that run vertically along the sides. It is found throughout the Gulf of Mexico and even into some freshwater habitats. The Florida Museum of Natural History also list this species as a marine invader4.
I am not sure how much seining you do along our waterways, but if you do any within the grassbeds you are sure to find one of these unique and interesting fish.
References
1 Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico. Texas A&M Press, College Station TX. Pp. 327.
2 Opossum pipefish. Discover Fishes. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/opossum-pipefish/.
3 Opossum Pipefish. Species of Concern. National Oceanic and Atmospheric Administration, National Marine Fisheries Service. https://www.nrc.gov/docs/ML1224/ML12240A312.pdf.
4 Gulf Pipefish. Discover Fishes. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/florida-fishes-gallery/gulf-pipefish/.
by Rick O'Connor | Feb 3, 2022
Seahorses are one of the coolest creatures on this planet – period. I mean who doesn’t like seahorses? People state “I love snakes”, “I hate snakes”, “I love sharks”, “I hate sharks”. But no one says, “I hate seahorses”. They are sort of in the same boat with sea turtles, everyone loves sea turtles. They are an icon of the sea, logos for beach products and coastal HOAs, underwater cartoons and tourist development boards, diving clubs and local restaurants. But have you ever seen one? I mean beyond seeing one at a local aquarium or such, have you ever found one while snorkeling on one of our beaches?
Most would say no.
I have lived in the panhandle all my life and have spent much of it in the water, and I can count on both hands the number of times I have encountered a seahorse while at the beach. Most encounters have been while seining. I cannot count on both hands how many times I have pulled a seine net here but very few of them did a seahorse encounter occur. When they did, it was over grassbeds. In each encounter the animal was lying in the grass not wriggling like the other fish, just lying there. It would be very easy to miss them discarding it as “grass”. It makes you wonder how many times I captured one and did not know it. When we did find one it was VERY exciting. My students would often scream “I had NO idea they lived here!”.
The seahorse Photo: NOAA
However, if you tried searching for them while snorkeling, which I have, the encounter rate is zero. But this makes sense. These animals are so well camouflaged in the grass it would be a miracle to find one just hanging there. This is by necessity really. If you have ever watched a seahorse in an aquarium they are not very “fleet of foot”. Escaping a predator by dashing away is not one of their finer skills. No, they must blend in and remain motionless if trouble, like a snorkeler, comes by.
But I have seen one while diving. It was a night dive near the Bob Sikes Bridge on Pensacola Beach about 40 years ago. We were exploring when my light swung over to see this large seahorse extended from a pipe that was coming out of some debris on the bottom. I was jubilated and screamed, as best you can while using SCUBA, for my partners to come check this out. We were all amazed and my interest in these animals increased.
When I attended Dauphin Island Sea Lab (DISL) as an undergraduate student, like many in the 1970s, I thought I would get involved with sharks, but I quickly developed a love for estuaries and my interest in seahorses returned. I made a visit to the library there and found very little in the literature, at that time, which piqued my interest even more. My senior year we had to complete a project where we had to collect, and correctly identify, 80 species of fish to pass the class. I asked the crew of the research vessel at DISL if they had ever found seahorses. They responded yes and took me to what they called their “seahorse spot”. We caught some. It was very cool. And yes… seahorses do exist here in the wild.
But what is this amazing animal?
What do I mean by this? As a marine science instructor, I would give my students what are called a lab practical’s. Assorted marine organisms would be scattered around the room and the students had to give their common name, phylum name, class name, and answer some natural history question I would ask. Snails are mollusk, mackerel are fish, jellyfish are cnidarians, and then they would come to the seahorse. Seahorses were… well… seahorses! What the heck are they?
Many of you may know they are fish. But over the years of teaching marine science, I found that many students were not sure of that. The definition of a fish is an animal with a backbone that possesses a scaly body, paired fins (usually), and gills. Seahorses have all that. There is a backbone no doubt. The scales are not as obvious because they are actually fused together in a sort of armor. The paired fins and gills are there. Yep… they are fish, but a fish (horse) of a different color.
This seahorse is a species from Indonesia.
Photo: California Sea Grant.
First, they are one of about 13 families of fish in the Gulf of Mexico that lack ventral fins, those on the belly side of their bodies. Second, they lack a caudal fin (the fish tail) and have a more prehensile tail for grabbing objects. Third, they swim vertically instead of horizontally as most fish do. Again, there is nothing about their body design that says “speed”.
Another thing I find fascinating about these animals is their global distribution. You might recall that the initial focus of this series on Florida panhandle vertebrates was the biogeography of these creatures. Seahorses are found all over the world. There are over 350 species of them. But the interesting question is: how would a seahorse living in the northern Gulf of Mexico reach Melbourne Australia? It makes sense that being so far apart there would be such differences in looks and genetics that they would be classified as different species, but how did an animal like a seahorse disperse across a large ocean like the Pacific?
Honestly, I can say the same for ghost crabs, which I found on the beaches of Hawaii. How did they get there? But that is another story.
My best guess was the dispersal occurred at a time when the two continents were closer together. The Pangea days, or some time close to that period. And as the continents “drifted” the seahorses remained close to their shorelines and moved apart. They may have been able to “island hop” across coral reefs to other Indonesian Islands, but those here in the United States were long lost relatives that changed in their appearance and lifestyles due to the large separation from others. That is my two cents anyway.
Hoese and Moore1 list two species of seahorses found here in the northern Gulf of Mexico. The Lined Seahorse and the Dwarf Seahorse.
The Lined Seahorse (Hippocampus erectus) is the larger of the two, reaching an average length of five inches. This is the one I found near the Bob Sikes Bridge all those years ago. Like all seahorses they are well adapted to life in debris where they can grab on to something with their prehensile tail and feed on small zooplankton using their vacuum like tube snout. Like all seahorses, the males have a brood pouch that holds the fertilized eggs producing live birth – another “live bearer”. They are usually dark in color, but gold individuals have been reported. Some have filamentous threads on their bodies making them look even more like plants. Their biogeographic distribution is amazing. They are found from Nova Scotia, throughout the tropics, all the way to Argentina. This suggests few biogeographic barriers, other than substrate to hide in.
The Dwarf Seahorse (Hippocampus zosterae) – also known as the pygmy seahorse – is much smaller, with a mean length of 1.5 inches. That would qualify as “dwarf” or “pygmy”. How would you ever find these? Other than size, the difference between these two are the number of rays (soft spines) in their fins. They can be counted, but its not fun, especially with a 1.5” seahorse. This guy prefers high salinity, actually, I have found that most seahorses do. This one is more tropical in distribution.
There is a third Florida species, the long snout seahorse (Hippocampus redi) that is found on the Atlantic coast, but not in the Gulf.
The strange thing about the seahorses in Florida, has been the declining encounters over the last few decades. For a creature that seems to have few barriers, they have found trouble somewhere. Maybe the loss of habitat, maybe a population crash due to the common practice years ago of capture and drying out for tourists to buy. It could be a change in environmental conditions such as salinity in the Pensacola Bay area. I am not sure. The more I write this article, the more my interest in this fish returns. As many researchers and wildlife managers have mentioned, this is an animal who has “fallen through the cracks”. People notice the changes in sea turtle and manatee encounters, but not seahorses. Maybe it is time we pay more attention to them and see how they are doing. I for one would hate to see the decline of this creature here in the panhandle.
Reference
Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press, College Station, TX. Pp. 327.
by Rick O'Connor | Feb 3, 2022
Based on our seine surveys along the beaches of most estuaries in the Florida panhandle, this is one of the most abundant fish in our bays. No matter the time of year, or the location, estuarine seining usually includes numerous individuals of this group. It is very apparent the importance they play in the food web of our local bays.
The silverside, or “glass” minnow.
Photo: U.S. Geological Survey
Those visiting and recreating in our waters probably are not aware of the numerous individuals of this fish schooling all around them. They are almost transparent and are often called “glass minnows” because of this. So, you do not really see them – even if you are snorkeling. But take a small hand net or a seine net and you will quickly discover they are there – and a lot of them.
They are small three-inch fish that are long, and tube shaped with forked (lunate) tails. Their bodies have a slight yellow-green appearance on the dorsal side, but much is a whiteish in color or transparent all together. They do have a broad silver stripe that runs laterally along their body and is where they get their common name “silversides”. Anchovies also have this “silverside” and are found in the same locations but differ from the silversides in that they have a more “shark looking snout” and only one dorsal fin, compared to the two dorsal fins found on the silversides.
It is apparent this whiteish, transparent color and silver stripe are effective in avoiding predation. Again, you and I do not see them while we are snorkeling. But is also apparent that many are consumed due to the large number you find in their schools. I have found from my seining surveys this fish is often collected on days when no other species are. The heat of summer, the cool of winter, during and after storms, high humidity, it does not matter – I always captured them. I have captured them over sandy beaches, over seagrasses, near jetties, and in the muck and mire of salt marshes. They are literally everywhere. I also capture them more frequently than I do anchovies, suggesting their importance to the health of the estuarine food web. It is one of the first fish my students learned to identify because of how frequently we caught them.
In the northern Gulf, there are two species found in local estuaries – the rough silverside and the tidewater silverside. Hoese and Moore1 do report a third species similar to the tidewater silverside that is more tolerant of saltwater.
The Rough Silverside (Membras martinica) is called so because their body scales are serrated and are “rough to the touch”. This is when you slide your fingers from the back towards the head, your fingers will feel the serrations and it is rough to the touch.
The Tidewater Silverside (Menidia beryllina) is smooth to the touch because their scales lack serrations. Other than that, these two fish look very similar. Tidewater silversides seem to be restricted to the shorelines and do not venture to the extended grassbeds off the beach. The third species mentioned M. peninsulae, is reported to prefer salinities at and above 19 ppt, where the tidewater prefers lower salinities. There is little else mentioned to distinguish these two, but I have seen both names reported in the scientific literature from researchers sampling our bay.
Both species of silversides have a large biogeographic distribution. Ranging from the colder waters of New York, all along the eastern seaboard, and the entire Gulf of Mexico.
You may not see them often, but know they are an important part of the estuarine ecology.
Reference
Hoese, H.D., Moore, R. H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press, College Station TX. Pp. 327.
by Rick O'Connor | Jan 27, 2022
Members of the family Poeciliidae are what many call “livebearers”. Live bearing meaning they do lay eggs as most fish do, but rather give birth to live young. But this is not to be confused with live-bearing you find in mammals – which is different.
Most fish lay eggs. The females and males typically have a courtship ritual that ends with the female’s eggs (roe) being laid on some substrate, or released into the water column, and the male’s sperm (milt) are released over them. Once fertilized the gelatinous covered eggs begin to develop.
Everything the developing young need to survive is provide within the egg. The embryo is suspended in a semi-gelatinous fluid called the amnion. Oxygen and carbon dioxide gas exchange occurs through this amnion and through the gelatinous covering of the egg itself. Food is provided in the form of yolk, which is found in a sac attached to the embryo. There is a second sac, the allantois, where waste is deposited. When the yolk is low and the allantois full – it is time to hatch. This usually occurs in just a few days and often the baby fish (fry) are born with the yolk sac still attached. Parental care is rare, they are usually on their own.
With “livebearers” in the family Poecillidae it is different.
The males have a modified anal fin called a gonopodium. They fertilize the roe not externally but rather internally – more like mammals. The fertilized eggs develop the same as those of other fish. There is a yolk sac and allantois, and the embryo is covered in amnion within the gelatinous egg covering. But these eggs are held WITHIN the female, not laid on the substrate or released into the water column. When they hatch the live fry swim from the mother into the bright new world – hence the term “livebearer”.
There are advantages to this method. The eggs are protected inside the mother, and she obviously provides parental care to her offspring. However, this does make her much slower and an easier target for predators. There is some give and take.
This differs from the “live-bearing” of most mammals in that there is still an egg. Mammals do still have a yolk sac but feeding and removing waste is done THROUGH THE MOTHER. Meaning the embryo is attached to the mother via an umbilical cord where the mother provides food and removes waste trough her placenta. There is no classic egg in this case. I say most mammals because there are two who live in Australia that still do lay eggs – the platypus and the spiny anteater, and the marsupials (kangaroos and opossums) are a little different as well – but marsupials do no lay eggs.
Biologists have terms for these. Oviparous are vertebrates that lay eggs – such as fish, frogs, turtles, and birds. Ovoviviparous are vertebrates that produce eggs but keep them within the mother where they hatch – such as some sharks, some snakes, and the live bearing fish we are talking about here. Then there are the viviparous vertebrates that do not have an egg but rather the embryo is attached, and fed by, the mother herself – like most mammals.
Sailfin Molly. The male is the fish above with the large “sailfin”. Note the gonopodium on his ventral side.
Photo: University of Florida
The livebearers of the family Poeciliidae are ovoviviparous. They are primarily small freshwater fish that are very popular in the aquarium trade. But there are two species that can tolerate saltwater and enter the estuaries of the northern Gulf of Mexico: the sailfin molly and the mosquitofish.
The Sailfin Molly (Poecilia latipinna) is the same fish sold in aquarium stores as the black molly. The black phase is quite common in freshwater habitats, but in the estuarine marshes the fish is more of a gray color with lateral stripes that is made up of a series of dots. They are short-stout bodied fish and the males possess the large sail-like dorsal fin from which the species gets its common name. The females resemble the males albeit no large sailfin and most found are usually round and full of developing eggs. They are very common in local salt marshes and often found in isolated pools within these habitats. The biogeographic range of this species is restricted to the southern United States, reported from South Carolina throughout the Gulf of Mexico. One would guess temperature may be a barrier to their dispersal further north along the Atlantic seaboard.
The mosquitofish.
Photo: University of Florida
The Mosquitofish (Gambusia affinis) is familiar to many people whether they know it or not. Those who know the fish know they are famous for the habit of consuming mosquito larva and some, including our county mosquito control unit, use them to control these unwanted flying insects. For those who may they are not familiar with it, this is the fish frequently seen in roadside ditches, ephemeral ponds that show up after rainstorms, retention ponds, and other scattered bodies of freshwater within the community. Most who see them call them “minnows”. There is always the question as to “where did they come from?” You have a vacant lot – it rains one day – these small fish show up – where did they come from? The same can be said for community retention ponds. The county comes in a digs a hole – it rains one day, and the retention pond fills – and there are fish in it. One explanation to their source is the movement of fish by wading birds, where the fish incidentally become attached to their feet. Again, they are often released intentionally to help control local mosquito populations. This fish is found in our coastal estuaries but does not seem to like saltwater as well as the sailfin molly. It is found in cooler water ranging throughout the Gulf and as far north as New Jersey.
Both of these fish make excellent aquarium pets, and the sailfin molly in particular can be beautiful to watch.
Reference
Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press, College Station TX. Pp. 327.
