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.
by Chris Verlinde | Nov 19, 2021
Photo: Chris Verlinde
Photo: Chris Verlinde
The diversity and natural beauty of the Escribano Point Wildlife Management area is breathtaking. These six square miles of conservation lands provides many types of outdoor recreation including: birdwatching, kayaking, camping, swimming, fishing and hiking. The bays, estuaries, river swamps and other coastal habitats are managed to preserve native plants and animals. Visit Escribano Point Wildlife Management Area (WMA) soon and discover this piece of old Florida.
The Escribano Point WMA is part of state-owned conservation lands that provide habitat for rare plants and animals and promote water quality in Blackwater Bay, East Bay and the Yellow River. The diverse habitats found in Escribano Point WMA provide home to many types of wildlife including, deer, turkey, Florida Black Bears, birds, reptiles amphibians and fish.
As part of the Florida Master Naturalist Program’s 20th Anniversary, a small but mighty group hit the water just as the air temperature broke 60 degrees on Saturday. We kayaked up Fundy Bayou and out to Fundy Cove located along the southeast side of Blackwater Bay in Santa Rosa County, Fl.
We traveled through freshwater and saltwater marshes, along scrubby flat woods, beach and mesic hammock habitats. Ospreys, a kingfisher, and red-headed woodpecker entertained the group. The air temperature warmed as we paddled. When we arrived at the junction of Fundy Creek and Blackwater Bay, Blackwater Bay was rough. We paddled to the campground for lunch and enjoyed the peaceful beauty around us.
Thanks to Kayak Dave, one member of the group checked an action on her bucket list to paddle again.
Escribano Point WMA is a treasure located in Santa Rosa County, FL., approximately 20 south of Milton, FL . Take some and visit for a day or two, there are 2 campgrounds located at this WMA. Enjoy!
by Rick O'Connor | Oct 21, 2021
Catfish…
There are a lot of fish found along the Florida panhandle that many are not aware of, but catfish are not one of them. Whether a saltwater angler who captures one of those slimy hardhead catfish to a lover of freshwater fried catfish – this is a creature most have encountered and are well aware of.
Growing up fishing along the Gulf of Mexico, the “catfish” was one of our nemesis. Slinging your cut-bait out on a line, if you were fishing near the bottom, you were likely to catch one of these. Reeling in a slimy barb-invested creature, they would swallow your bait well beyond the lip of their mouths and it would begin a long ordeal on how to de-hooked this bottom feeder that was too greasy to eat. Many surf fishermen would toss their bodies up on the beach with the idea that removing it would somehow reduce their population. Obviously, that plan did not work but ghost crabs will drag their carcasses over to their burrows where they would consume them and leave the head skull that gives this species of catfish it’s common name “hardhead” catfish, or “steelhead” catfish. This hard skull has bones whose shape remind you of Jesus being crucified and was sold in novelty stores as the “crucifix fish”.
The bones in the skull of the hardhead catfish resemble the crucifixion of Christ and are sold as “crucifix fish”.
Photo: Rick O’Connor
When I attended college in southeast Alabama a group of friends wanted to go out for fried catfish. I, knowing the above about saltwater catfish, replied “why?… no…, you don’t eat catfish”. They assured me you did and so off we went to a local restaurant who sold them. Fried catfish quickly became one of my favorites. A fried catfish sandwich with slaw and beans is something I always look forward to. At that time, I was not aware of the freshwater catfish, nor the catfish farms that produce much of the fish for my sandwiches. I now have also become aware of the method of catching freshwater catfish called “noodling” – which is not something I plan to take up.
Worldwide, there are 36 families and about 3000 species of what are called catfish1. Most are bottom feeders with flatten heads to burrow through the substrate gulping their prey instead of biting it. Most possess “whiskers” – called barbels, which are appendages that can detect chemicals in the environment (smell or taste) helping them to detect prey that is buried or hard to find in murky waters. These barbels resemble whiskers and give them their common name “catfish”.
The serrated spines and large barbels of the sea catfish. Image: Louisiana Sea Grant
They lack scales, giving them the slimy feel when removing them from your hook, and also have a reduced swim bladder causing them to sink in the water – thus they spend much of their time on the bottom. The mucous of their skin helps in absorbing dissolved oxygen through the skin allowing them to live in water where dissolved oxygen may be too low for other types of fish1.
They are also famous for their serrated spines. Usually found on the dorsal and pectoral fins, these spines can be quite painful if stepped on, or handled incorrectly. Some species can produce a venom introduced when these spines penetrate a potential predator which have put some folks in the hospital1.
The size range of catfish is large; from about five inches to almost six feet. In North America, the largest captured was a blue catfish (Ictalurus furcatus) at 130 pounds. The largest flathead catfish (Pylodictis olivaris) was 123 pounds. But the monster of this group is the Mekong catfish of southeast Asia weighing in at over 600 pounds.
The Florida Fish and Wildlife Conservation Commission lists six species of catfish in the Florida panhandle area. However, they are focusing on species that people like to catch2.
The Blue Catfish
Photo: University of Florida
This large blue catfish is being weighed by FWC researchers. Photo: Florida Fish and Wildlife Conservation Commission
The Channel Catfish (Ictalurus punctatus) is found throughout Florida and also in many river systems of the eastern United States. It has found few barriers dispersing through these river systems. They are not typically bottom feeders having a more carnivorous diet.
The Flathead Catfish (Pylodictis olivaris) are relatively new to Florida and are currently reported in the Escambia and Apalachicola rivers. They prefer these slow-moving alluvial rivers.
The Blue Catfish (Ictalurus furcatus) were first reported in the Escambia and Yellow Rivers, there are now records of them in the Apalachicola. These catfish prefer faster moving rivers with sand/gravel bottoms and seem to concentrate towards the lower ends of major tributaries.
The White Catfish (Amerius catus) is found in rivers and streams statewide, and even in some brackish systems.
The Yellow Bullhead (Amerius natalis) are most often found in slow moving heavily vegetated systems like ponds, lakes, and reservoirs. It is reported to be more tolerant of poor water conditions.
The Brown Bullhead (Amerius nebulosus) live in similar conditions to the Yellow Bullhead.
The dispersal of freshwater catfish is interesting. How do they get from the Escambia to the Apalachicola Rivers without swimming into the Gulf and up new rivers? The answer most probably comes from small tributaries further upstream that can, eventually, connect them to a new river system. Scientists know that eggs deposited on the bottom can be moved by birds who feed in each of the systems carrying the eggs with them as they do. And you cannot rule out movement by humans, whether intentionally or accidentally.
On the saltwater side of things, there are two species – though the blue catfish has been reported in the upper portions of some estuaries in low salinities in the western Gulf of Mexico. The marine species are the hardhead catfish (Arius felis), sometimes known as the “steelhead” or the “sea catfish” – and the gafftop (Bagre marinus), also known as the gafftopsail catfish3.
The hardhead catfish is very familiar with anglers along the Gulf coast. This is the one I was referring to at the beginning of this article. It is considered inedible and a nuisance by most. They are common in estuaries and the shallow portions of the open sea from Massachusetts to Mexico. They are reported to have an average length of two feet, though most I have captured are smaller. Like many catfish, they possess serrated spines on their dorsal and pectoral fins. Their distribution seems to be limited by salinity.
The gafftop is also reported to have a mean length of two feet, and most that I have captured are closer to that. At one point in time, we were longlining for juvenile sharks in Pensacola Bay and caught numerous of these thinking they were small bull sharks as we pulled the lines in, until we saw the long barbels extending from them. I remember this being a very slimy fish, covered with mucous, and not fun to take off the hooks. It is reported to have good food value, though I have not eaten one. They differ from the hardheads mainly in their extended rays from the dorsal and pectoral fins. The habitat and range are similar to hardheads, though they have been reported as far south as Panama.
The extended rays of the gafftop catfish.
Photo: University of Florida.
The diversity of freshwater catfish in the U.S. goes beyond what has been reported here. This group has been found on most continents and have been very successful. There are plenty of local catfish farms where you can try your luck, have them cleaned, and enjoy a good meal.
References
1 Catfish. Wikipedia. https://en.wikipedia.org/wiki/Catfish.
2 Catfish. Florida Fish and Wildlife Conservation Commission. https://myfwc.com/fishing/freshwater/sites-forecasts/catfish/.
3 Hoese, H.D., R.H. Moore. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M Press. College Station TX. Pp. 327.
by Ray Bodrey | Apr 20, 2021
Scott Jackson, UF/IFAS Extension Bay County & Florida Sea Grant
Ray Bodrey, UF/IFAS Extension Gulf County & Florida Sea Grant
Erik Lovestrand, UF/IFAS Extension Franklin County & Florida Sea Grant
Can you remember where you were one year ago last April? The uncertainty of each day seemed to go on forever. At this time last year, we were planning several education programs that eventually had to be canceled or migrated to online events. Scallop Sitters was one of our cooperative volunteer programs with Florida Fish and Wildlife (FWC) that was postponed during the pandemic in 2020. Thankfully, FWC biologists continued restoration work last year in the region with good results and steps forward. However, there was something painfully absent in these efforts – you!
One of the lessons last year taught us, is to appreciate our opportunities – whether it is to be with your family, friends, or serve your community freely through volunteer service. Some new service opportunities appeared while others were placed on hold. Thankfully, we are excited to announce the Scallop Sitters Citizen Scientist Restoration Program is returning to our area in St. Andrew, St. Joe, and Apalachicola Bays this summer!
Historically, populations of bay scallops were in large numbers and able to support fisheries across many North Florida bays, including St Andrew Bay. Consecutive years of poor environmental conditions, habitat loss, and general “bad luck” resulted in poor annual scallop production and caused the scallop fishery to close. Bay scallops are a short-lived species growing from babies to spawning adults and dying in about a year. Populations can recover quickly when growing conditions are good and can be decimated when conditions are bad.
An opportunity to jump start restoration of North Florida’s bay scallops came in 2011. Using funding as a result of the Deepwater Horizon Oil Spill, a multi-county scallop restoration program was proposed and eventually established in 2016. Scientists with FWC use hatchery reared scallops obtained from parents or broodstock from local bays to grow them in mass to help increase the number of spawning adults near critical seagrass habitat.
FWC also created another program where volunteers can help with restoration called “Scallop Sitters” in 2018 and invited UF/IFAS Extension to help manage the volunteer portion of the program in 2019 which led to targeted efforts in Gulf and Bay Counties.
After a year’s hiatus, UF/IFAS Extension is partnering with FWC again in Bay and Gulf Counties and expanding the program into Franklin County. Despite initial challenges with rainfall, stormwater runoff, and low salinity, our Scallop Sitter volunteers have provided valuable information to researchers and restoration efforts, especially in these beginning years of the program.
Volunteers manage predator exclusion cages of scallops, which are either placed in the bay or by a dock. The cages provide a safe environment for the scallops to live and reproduce, and in turn repopulate the bays. Volunteers make monthly visits from June until January to their assigned cages where they clean scallops removing attached barnacles and other potential problem organisms. Scallop Sitters monitor the mortality rate and collect salinity data which determines restoration goals and success in targeted areas.
You are invited! Become a Scallop Sitter
1.Register on Eventbrite
2.Take the Pre-Survey (link will be sent to your email address upon Eventbrite Registration)
3.View a Virtual Workshop in May
4.Attend a Zoom virtual Q & A session in May or June with multiple dates / times available
5.Pick up supplies & scallops on June 17 with an alternate pick-up date to be announced
UF/IFAS Extension is an Equal Opportunity Institution.
by Chris Verlinde | Jan 22, 2021
Santa Rosa Portion of the Oyster Mapping and Assessment Project
Santa Rosa County R.E.S.T.O.R.E. has funded the SRC Oyster shell recycling program and the Pensacola, East and Blackwater Bays Intertidal and Subtidal Oyster Reef mapping and Assessment projects. The Nature Conservancy is managing the oyster reef mapping and assessment project and has contracted with MREC Environmental, LLC to get the work done.
The purpose of the project is to map and assess the condition of known and potential intertidal and subtidal oyster reef resources in the Santa Rosa County portion of the Pensacola Bay system. Results of this mapping project will establish a baseline of the existing locations and condition of oyster resources in SRC. This information will help to guide future restoration projects.
Subtidal oysters are harvested in clumps and are culled using a large knife or hatchet. Photo credit: Calvin Sullivan
Intertidal reefs are typically exposed at low tides and found along the shoreline of our bay system. Sub-tidal reefs are found under water. Gabe Johnson, owner of MREC Environmental has verified existing intertidal reefs using a jet-ski in the fall of 2020. Our bay system does not have as many natural intertidal reefs as in other parts of Florida. There are existing intertidal reefs that have been installed for shoreline protection and habitat enhancement.
Gabe Johnson and the crew of MREC Environmental are working to complete the initial bottom survey in early 2021. He has set up grids based on historic locations of oyster reefs throughout the Santa Rosa County portion of the Pensacola Bay system. He will then verify his findings by diving sites where oyster shell was found during the bottom survey.
From left to right: Dale, Gabe and Reese of MREC Environmental. Phot credit: Chris Verlinde
Side scan sonar and echosounder along the side of the boat. Photo Credit: Chris Verlinde
Gabe and his crew are using one Side Scan Sonar, an Edgetech 4125i to map images of the bottom. The other instrument they are using is a Singlebeam Hydrographic Echosounder (Teledyne Odom Echotrac CV100). The echosounder is used to collect water depth data and contours of the water bottom. The echosounder is connected to a transducer. The side scan sonar and the transducer from the ecosounder are placed along the side of the boat and submerged while the boat travels over the transects to collect the underwater images and parameters.
The pink lines are the transect lines of grid #25. Photo credit: Chris Verlinde
About two thirds of grid #25 are completed. Photo credit: Chris Verlinde
Dale dropping the pole to assess bottom characteristics. Photo credit: Chris Verlinde
On a cold day in December 2020, Gabe and his crew covered 149.3 acres in grid #25, just west of the power lines in East Bay. Grid 25 included 32 parallel transect lines (2468 feet long), spaced 100 feet apart. This grid was completed in approximately three and a half hours by running the boat along each transect and recording data. In addition to the electronic data, one of the crew members used a fiberglass pole to assess bottom conditions. Approximately, every 10 feet or so, the pole guy would lower the pole and shout the condition of the bottom, either sand, mud, or shell. Gabe then recorded the point and code on his mapping software.
Image from the side scan sonar showing a sand bottom. Photo credit: Chris Verlinde
Side scan image of bottom with showing potential shell (the darker scatter area). Photo credit: Chris Verlinde
The raw data will be compiled into maps and a report that will be used to based future oyster fishery and habitat enhancement restoration efforts in East, West and parts of Escambia Bay.
by Carrie Stevenson | Aug 27, 2020
Carrie Stevenson is the Coastal Sustainability Agent for the UF/IFAS Escambia County Extension Office, and has been with the organization almost 17 years. Her educational outreach programs focus on living sustainably within a vulnerable coastal ecosystem. She helps clientele better understand how to protect and preserve local ecosystems and water resources, wisely use our abundant rainfall and sunlight, and prepare and mitigate for flooding, coastal storms and climate impacts.
Growing up an avid reader and science junkie, a young Carrie aspired to find a career that allowed her to “be outdoors and wear jeans,” and in college sought to become a science writer. When National Geographic didn’t come calling, she found a position as a field-based environmental specialist with the Florida Department of Environmental Protection. There, she handled compliance and enforcement cases related to stormwater and wetlands, spending days tromping through the swamps, wet prairies, and newly built subdivisions of northwest Florida. After joining UF IFAS Extension, she spent 6 years as a Florida Yards & Neighborhoods Agent before switching to Coastal Sustainability. Her expertise and articles focus on climate issues, stormwater, hurricanes, native plants, and wetlands.
A lifelong outdoors enthusiast, she enjoys biking, standup paddleboarding, and traveling to national parks with her family. She also has many favorite international outdoor experiences, ranging from hiking glaciers in Canada to snorkeling coral reefs in Belize and watching elephants drink from a South African river. A native of Mississippi, Carrie has lived with her husband in Pensacola since 1999. Carrie earned her master’s degree in Biology/Coastal Zone Studies from the University of West Florida in Pensacola and an undergraduate degree in Marine Science from Samford University (Birmingham, Alabama). She is the proud mom of an Eagle Scout and leads her daughter’s Girl Scout troop. She is a Fellow in the Natural Resources Leadership Institute (NRLI), past president of the Florida Association of Natural Resource Extension Professionals (FANREP), and member of IMPACT 100 Pensacola Bay.
