The Great Scallop Search; Pensacola Bay 2023

The Great Scallop Search; Pensacola Bay 2023

Introduction

Bay scallops (Argopecten irradians) have been an important part of the economy of many gulf coast communities within the Florida Big Bend for decades.  It was once abundant in all gulf coast counties of the state but beginning in the 1960s populations in many bays began to decline to levels where they are all but nonexistent.  The cause of this decline has been associated with many factors including a decline in water quality, a decline in suitable habitat (sea turtle grass beds – Thalassia), and overharvesting.  Most likely the cause included all of these.  Since the collapse of both the commercial and recreational fishery, Gulf coast communities have been trying to address all three of the stressors above.  Multiple monitoring projects are ongoing in the Pensacola Bay area and one of those is the Great Scallop Search.  

The Great Scallop Search was developed by Sea Grant Agents in Southwest Florida and expanded, through Florida Sea Grant, to Northwest Florida.  In each location volunteers snorkel a 50-meter transect line searching for live bay scallops, as well as monitoring the status of the seagrass habitat.  Since 2015 317 volunteers have logged 634 hours surveying 407 50-meter transects in 106 grids in Big Lagoon or Santa Rosa Sound.  In that time 4 live scallops have been logged, though we hear anecdotal reports of additional scallops being found in these bodies of water. 

Survey Method

Volunteers select and survey one of 11 grids in Big Lagoon, or one of 55 grids in Santa Rosa Sound.  Once on site, the volunteers anchor and record preliminary information on the data sheet provided.  Two snorkelers enter the water and swim on opposite sides of a 50-meter transect line searching for live scallops.  Any live scallop found is measured and returned.  The species and density of the seagrass is recorded as well as the presence/absence of macroalgae on that seagrass.  Four such transects are surveyed in each grid. 

2023 Results

2023SRSBLTotalOther
# of volunteers    72No significant difference between 2022 and 2023
# of grids surveyed8816Slight decrease from 2022.  16 of the 66 grids (24%) were surveyed. 
# of transects surveyed265177A decrease from 2022.  More surveys were conducted in Big Lagoon than Santa Rosa Sound. 
Area surveyed (m2)2600510077001.9 acres
# of scallop found2  24Four live scallops are a record for this project.  It equals the sum of all other live scallops since the project began. 
Scallop Size (cm)4.5, 5.04.0, 4.5  
Surveys with Seagrass    
Halodule5121717/21 surveys – 81%
Thalassia8111919/21 surveys – 90%
Syringodium0222/21 surveys – 10%
Grass Density    
100% grass391212/21 surveys (57%) were 100% grass
90%101Note: Volunteers typically select area for transects
75%314with a lot of grass.
70%101 
50%3912 
5%101 
Macroalgae    
Present448 
Absent2101212/21 surveys (57%) had no macroalgae.
Abundant224 
Sediment Type    
Mud011 
Sand781515/21 surveys (71%) were sandy.
Mixed145 

21 surveys were conducted covering 16 grids.  8 grids were surveyed in each body of water. 

A total of 77 transects were conducted covering 7,700 m2 and four live scallops were found. 

Two of the scallops were found in Big Lagoon and two in Santa Rosa Sound. 

All scallops measured between 4-5cm (1.6-2”). 

The number of live scallops found this year equaled the total number found over the last eight years. 

Most of the transects included a mix of Halodule and Thalassia seagrass ranging from 100% coverage to 5%.  The majority of the transects were between 50-100% grass.  Four transects had 100% Thalassia.  Three of those were in Santa Rosa Sound, one was in Big Lagoon.  The diving depth of the volunteers ranged from 0 meters (0 feet) to 2.4 meters (8 feet).  Macroalgae was present in 8 of the 21 surveys (38%) but was not abundant in most. 

Volunteer measuring one of the four collected bay scallops in 2023 from Pensacola Bay. Photo: Gina Hertz.

Summary of Project

YearVolunteerGrids SurveyedTransects SurveyedLive Scallops Found
201587281010
201696311111
201754160
2018207320
2019136200
202052161
2021176240
20227422872
20237216774
TOTAL3174078
MEAN3514450.4

To date we are averaging 35 volunteers each event, surveying 14 of the 55 possible grids (25%).  We are averaging 45 transects each year (4500 m2), have logged 407 transects (40,700 m2) and have recorded 8 live scallops (< than one a year). 

Discussion

Based on the results since 2016 this year was a record year for live scallops.  Whether they are coming back on their own is still to be seen.  Being mass spawners, bay scallop need high densities in order to reproduce successfully, and these numbers do not support that.  The data, and comments from volunteers, suggest that the grasses look good and dense.  Thalassia, a favorite of the bay scallop, appear to be becoming more abundant.  This is a good sign. 

Though small and few, bay scallops are trying to hold on in Pensacola Bay. Photo: Gina Hertz
Meet the Barnacle

Meet the Barnacle

You might say this is a strange title – “meet the barnacle” – because everyone knows what a barnacle is… or do they? 

As a marine science instructor, I gave my students what is called a lab practical.  This is a test where you move around the room and answer questions about different creatures preserved in jars.  Almost every time that got to the barnacle they were stumped.  I mean they knew it was a barnacle but what kind of animal is it?  What phylum is it in? 

Going through a thought process they would more often than not choose that it was a mollusk.  This makes perfect sense because of the calcium carbonate shell it produces.  As a matter of fact, science thought it was a mollusk until 1830 when the larval stage was discovered, and they knew they were dealing with something different.  It is not a mollusk.  So… what IS it?  Let’s meet the barnacle…

Barnacles along the seashore is a common site for many. Photo: NOAA

The barnacle is actually an arthropod.  Yep… the same group as crabs and shrimp, insects and spiders.  Weird right…

But that is because the creature down within that calcium carbonate shell is more like a tiny shrimp than an oyster.   It is in the class Cirripedia within the subphylum Crustacea.  It is the only animal in this class and the only sessile (non-motile) crustacean. 

Barnacles are exclusively marine.  This has been helpful when conducting surveys for terrapins or assessing locations for living shorelines – if you see barnacles growing on rocks, shells, or pilings, it is salty enough.  There are over 900 species described and they live independently from each other attached to seawalls, rocks, pilings, boats, even turtle shells.  Louis Agassiz described the barnacle as “nothing more than a little shrimplike creature, standing on its head in a limestone house kicking food into its mouth.” 

This image from a textbook shows the internal structure of a barnacle. Notice the shrimplike animal on its back with extendable appendages (cirri) for feeding. Image: Robert Barnes Invertebrate Zoology.

The planktonic barnacle larva settles to the bottom and attaches to a hard substrate using a cement produced from a gland near the base of their first set of antenna (crustaceans, unlike insects and spiders, have two sets of antenna).  It is usually head down/tail up and begins to secrete limestone plates forming the well known “shell” of the animal.  Some barnacles produce a long stalk near the head end (called the peduncle) which holds the adhesive gland and it is the peduncle that attaches to the hard substrate, not the head directly.  The goose neck barnacle is an example of this.  We find them most often in the wrack along the Gulf side of our beaches attached to driftwood or marine debris. 

Lucky was found in the Gulf of Mexico. He had been there long enough for these goose neck barnacles to attach and grow. Photo: Bob Blais

The “shell” of the barnacle is a series of calcium carbonate plates they secrete.  These plates overlap and are connected by either a membrane or interlocking “teeth”.  The body lies 90° from the point of attachment on its back. 

There are six pairs of “legs” which are very long and are extended out of the “doors” of the shell and make a sweeping motion to collect planktonic food in the water column.  They are most abundant in the intertidal areas were there are rocks, seawalls, or pilings. 

Most species are hermaphroditic (possessing both sperm and egg) but cross fertilization is generally the rule.  Barnacles signal whether they are acting males or females via pheromones and fertilization occurs internally, the gametes are not discharged into the water column as in some mollusks and corals.  The developing eggs brood internally as well.  Our local barnacle (Balanus) breeds in the fall and the larva (nauplius) are released into the water column in the spring by the tens of thousands.  The larva goes through a series of metamorphic changes until it settles on a hard substrate and becomes the adult we know.  They usually settle in dense groups in order to enhance internal fertilization for the next generation.  Those who survive the early stages of life will live between two and six years. 

So, there you go… this is what a barnacle is… a shrimplike crustacean who is attached to the bottom by its head, secretes a fortress of calcium carbonate plates around itself, and feeds on plankton with its long extending legs.  A pretty cool creature. 

Reference

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

Whale I’ll Be!

Whale I’ll Be!

We are fortunate to have several whale species that have been spotted in the Gulf of Mexico including humpback whales, Rice whales, fin whales, sperm whales, sei whales, and orca whales. Recently, however, we have seen multiple reports of whale sharks near shore in Destin and Panama City Beach. 

Whale sharks, however, are not whales, but the largest shark species and the largest fish alive today.  Whale sharks aren’t even closely related to whales.   They have gills, not blow holes.  They are huge, up to 46 feet in length and weigh up to 22,000 lbs., the weight of two African elephants.  Despite their large size, they are filter feeders with plankton being their main food, although they are also known to eat squid, krill, and small baitfish. They glide through the water at speeds of less than 3 m/hr, gently swinging their bodies side to side. They are not aggressive and pose no threats to humans.

Whale sharks prefer warm water, which is why they can be found in tropical areas and are often attracted to coastal areas due to a higher abundance of food. It’s no surprise, then, that they have been spotted in the Gulf. June to October is whale shark season in the Gulf, with Destin sightings being reported previously in 2013 and 2020. They are also found in many other countries around the world including Mozambique, Philippines, Honduras, Ecuador, Australia, Belize, Thailand, Egypt, Mexico, Seychelles, and the Maldives.

Unsurprisingly, many ocean lovers are desperate to get a glimpse of these majestic creatures in the water. However, experts recommend a hands-off policy for these gentle sea creatures.  The Okaloosa Coastal Resource Team has been collaborating with NOAA scientists at the University of Southern Mississippi to tag 10 of this year’s visitors to gain valuable insights into their migratory patterns and habitat use. You can follow their Facebook page for updates on current locations and tracking data. https://www.facebook.com/whalesharkresearch

Dotty, a 25 foot female whale shark tagged off Destin, Florida in July 2023 (Alex Fogg).
The Molting of Crabs

The Molting of Crabs

One of the community science volunteer projects I oversee in the Pensacola area is the Florida Horseshoe Crab Watch.  The first objective of this project is to determine whether horseshoe cabs exist in your bay – FYI, they do exist in Pensacola Bay.  The second objective is to determine where they are nesting – we have not found that yet, but we have one location that looks promising.  One of the things my volunteers frequently find are the molts of the horseshoe crabs.  Many keep them and I have quite a few in my office as well.  One volunteer was particularly interested in the fact that they even molted and that they could leave this amazing empty shell behind and yet still be crawling around out there.  So, I decided to write an article explaining the process in a little more depth than I typically do. 

Horseshoe crab molts found on the beach near Big Sabine. Photo: Holly Forrester.

I titled the article “The Molting of Crabs” but it could be the molting of any member of the Phylum Arthropoda – they all do this.  The Phylum Arthropoda is the largest, most diverse, and successful group of animals on the planet.  There are at least 750,000 species of them.  This is three times the number of all other animal species combined.  One thing unique to this group is the presence of an exoskeleton. 

The exoskeleton is made of chiton and is secreted by the animal’s hypodermis in two layers.  It provides the protection that the calcium carbonate shells of mollusk do but is much lighter in weight and allows for much more movement.  Arthropods have jointed legs, hence their name “arthropod – jointed foot”, to enhance this movement even more.  The entire body is covered by this exoskeleton. 

The outer layer is thin and called the epicuticle.  It is composed of proteins and, in many arthropods, wax.  The inner layer is the thicker procuticle.  The procuticle consists of an outer exocuticle and an inner endocuticle.  These are composed of chiton and protein bound to form a complex glycoprotein.  The exocuticle is absent at joints in the legs and along lines where the shell will rupture during molting.  In the marine arthropods the procuticle includes salts and minerals.  Where the epicuticle is not waxy and is thin, gases and water can pass into the animal’s body.  The cuticle also has small pores that allow the release of compounds produced by glands within the animal.  Not all of the cuticle is produced on the outside of the body.  Some portions of it are produced around internal organs. 

The colors of the crabs and other arthropods are produced by concentrations of brown, yellow, orange, and red melanin pigments within the cuticle.  Iridescent greens, purples, and other colors are produced by striations of the epicuticle refracting light. 

One disadvantage of the protective exoskeleton is the fact that it does not grow as fast as the interior soft tissue.  They have solved this problem by periodic shedding, or molting, of the shell.  Science calls this ecdysis, but we will continue to call it “molting”. 

Step one is the detachment of the hypodermis from the skeleton.  The hypodermis now secretes a new epicuticle.  Step two, the hypodermis releases enzymes which pass through the new epicuticle and begin to erode the untanned endocuticle of the old skeleton.  During this process the muscles and nerves are not affected and the animal can continue to move and feed.  Step three, the old endocuticle is now completely digested.  With the new procuticle produced by the hypodermis, the animal is now encased by both the old and new skeleton.  Step four, the old skeleton now splits along predetermined lines, and the animal pulls out of the old skeleton.  The new exoskeleton is soft – hence, the “soft-shelled blue crab” – and can be stretched to cover the increased size of the new animal.  This stretching occurs due to tissue growth during steps 1-3, and from the uptake of air and water.  The hardening of the new skeleton occurs due to the tanning of the new cuticle. 

Stages between molts become longer as the animal grows older.  Thus, there are numerous molts when the animal is young and as they age, they become fewer and farther between.  Most insects have a finite number of molts they will go through.  The marine arthropods seem to molt throughout their lives, though some species of crabs cease molting once they reach sexual maturity. 

Molting is under hormonal control.  Ecdyisone is secreted by certain endocrine glands, circulated through the blood stream, and acts directly on the epidermal cells.  There are hormones that, if secreted, will inhibit the molting process.  These are usually released if the animal senses trouble and that is not a good time. 

During the period when the old shell is being digested many of the salts and minerals are absorbed by the tissue of the animal.  Some people can eat crab but have allergic reactions when consuming soft shell crabs – most likely due to the increased salts and minerals in the tissue at this time.  During step 3, many crustaceans will seek shelter and will remain there for a period of time after molting allowing the new shell to harden.  The regeneration of lost limbs occurs during the molting process as well. 

Molts of many species are hard to find because the “soft-shelled” animal can consume the molt to increase needed salts and minerals – or other marine animals may do so for the same reason.  But horseshoe crab molts are pretty common and cool to collect.  Another common molt found is that of the cicadids in the pine forest areas of our panhandle.  The entire process is pretty amazing. 

Reference

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

A Sea of Grass; Part 10 – The Fish

A Sea of Grass; Part 10 – The Fish

When visiting and exploring seagrass beds, most are hoping, and expecting, to see fish.  As we have seen in this series, there are a lot of creatures that can be found living within a seagrass meadow, but it is the fish that get our attention and what we talk most about afterwards. 

According to Hoese and Moore’s Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters, there are 497 species of fish found in the Gulf of Mexico.  In my surveys of Pensacola Bay over the years, I have logged 101 of those in the estuary.  I am sure there are more, but I can confirm there are at least those.  Many spend all or part of their time in our seagrasses.  As you seine or snorkel in the grassbeds you will notice most of them are very small.  Much of this is due to the fact that the seagrasses are nursery areas for many species, and it is the young that we find here.  But many are also small as adults, and the grass provides food and shelter for them.  There are far too many to mention in an article like this, but let’s look at some of them. 

Sardines and Anchovies

As you snorkel through the grass, or even look at it from a boat or dock, you see numerous silver colored baitfish flashing as they dart in and out of the grass.  There are all sorts of silver baitfish in the seagrasses with sardines and anchovies being two of them.  In my experience seining for fish, they appear to be seasonal.  I did not capture them all year but when I did, I would capture a lot.  These species are famous for being the ones in small tins that people consume, though there is no fishery for them here locally.  Anchovies have also been considered an indicator species; their presence suggests good water quality. 

The striped anchovy is a fish often found in our seagrass beds. Photo: NOAA.

Silverside Minnows

Also known as silversides and glass minnows, these are one of the most common fish collected in seine nets.  They are abundant year-round and are an important food source for many of the larger predators living here.  Small and transparent, you do not see them while snorkeling.  Their huge presence is only discovered when you pull a seine net through the grass.  There are several species of them, but they are not easily identified and more often are just logged as “silversides”.  They are an important member of the seagrass community. 

The silverside, or “glass” minnow. Photo: U.S. Geological Survey

Seahorses and Pipefish

These two fish are highly specialized for living in seagrasses.  They look like grass and move very little making them hard to detect.  Like silverside minnows, it is rare to see them while snorkeling but make their presence known when seining.  Their bodies are covered in armor-like scales, and they have tubed mouths for “vacuuming” small invertebrates from the water column.  They are very slow swimmers and have to avoid detection by blending in with the environment.  And yes, it is the males that carry the eggs in their brood pouches.  These are amazing fish and always bring excitement when they are captured in the net.  There are two species of seahorses and seven species of pipefish found in our waters. 

The seahorse-like pipefish. Photo: University of Florida

Killifish

Often called “bull minnows” by anglers, these small fish are, at times, very abundant.  There are seven species of killifish in our bays but the Gulf Killifish, Longnose Killifish, and the Bayou Killifish are the ones we most often collected. 

This longnose killifish has the rounded fins of a bottom dwelling fish.

Needlefish

These are common, frequently seen, fish swimming at the surface of the water.  Long and needle-shaped, these fish have long snouts full of sharp teeth indicating they are one of the predators of this system.  There are four species of them, and they are not easy to tell apart.  They are harmless to humans unless you capture them in your net at which time they will try to bite. 

Swimming near the surface is a common place to find needlefish. Photo: Florida Springs Institute

Mullet

Another very common fish found year-round here.  This species are the ones famous for jumping while you are fishing, paddling, or just watching from the beach.  Those who do not visit the Gulf coast often always ask “I just saw a fish jump!” and the reply from a local (without even looking up to see what it was) will reply “It’s a mullet”.  These schooling fish can get pretty large (average length is 30 inches) and it is common to see fishermen out with their cast nets trying to catch a few.  It is a popular food fish for those along the Gulf coast.  Mullet fries, with beans and grits, are a way of life here.  The fish are easily seen swimming and darting over the grass as you paddle by, and their young are found seasonally in seine nets.  They are bottom feeders, feeding mostly on algae from the grass blades.  There are actually two species, the white and the striped mullet.  The striped mullet, also known as the black mullet, is the one most often sold in the seafood markets. 

The Striped Mullet. Image: LSU Extension

Drums and Croakers

With 18 species within this family, this is the largest family of inshore fish in the Gulf.  Growing up along the panhandle people learn quickly about croakers.  Back in the day when gill nets were used to harvest mullet, croakers were a common catch as well, and often consumed.  Today they are still sought by some shore-based anglers and juveniles are common in seine nets.  The species I most often captured were the spot and Atlantic croaker.  Spot croakers were common year-round, Atlantic croakers were more seasonal.  

Drums are larger members of this family.  There are several species more associated with sandy bottoms and the shoreline of the Gulf, many of these are called whiting, but the red drum (redfish) and black drum can be found in the grassbeds.  Redfish are particularly common here and one of the reasons many anglers get out of bed in the morning.  They are very popular sportfish across the region.  Black drums are not found as often, and like being around pilings and structures that offer certain foods they prefer.  Both species can get quite large.  Redfish average 5 feet while black drums can reach an average of 3 feet.

All of the fish in this family are famous for their “croaking” “drum” sounds they make using their swim bladder, and it is rare not to capture at least one kind in a seine net. 

The classic look of a bottom fish. This is the redfish, or red drum. Photo: NOAA

Spotted Seatrout; Speckled Trout; “Specks”

There is no “trout family” in the fish world.  Most freshwater trout are members of the salmon family while the marine versions are members of the drum/croaker family.  This is the case with the famous speckled trout – or speck.  There are white trout and silver seatrout in this family, and all are sought after by anglers, but it is the speckled trout that is most associated with seagrasses, most sought after by anglers, and is one of the top predators in this system.  They reach an average length of 4 feet. 

Spotted Sea Trout – Cynoscion nebulosus http://www.floridasportsman.com/sportfish/seatrout/

Pinfish and Sheepshead

From my experience both snorkeling and seining the grasses, I would say – hands down – that pinfish is the most common species found in our grasses.  For many young anglers this is the first fish they ever catch.  You can see them easily while snorkeling and they are the most numerous species in the nets throughout the year.  Their huge numbers play an important role in the food web of this system.  Feeding on a variety of small invertebrates in and around the grass blades, pinfish are a large part of the diet of the larger sportfish we target.  Throwing cast nets and dropping pinfish traps is popular with anglers to collect this abundant baitfish for their life bait fishing efforts.  They are called pinfish because of the sharp spines in their dorsal fins.  These are also the fish that nip at your ankles while you are standing still in the water. 

Sheepsheads are larger members of the porgy family (the ones these two species belong to).  As adults sheepsheads prefer hard structure where they can use their incisors to chip away at barnacles and other shellfish, but they are sometimes found roaming the grassbeds and their young will spend their growing years hiding and feeding in the grass. 

One of the most common fish in our grassbeds; the pinfish. Photo: Nicholls State University.

Pigfish

When first captured in the seine net, pigfish are often confused with pinfish – they look very similar.  But a closer look at the striping/spotted pattern on their sides, and the position of their mouth, you realize you have something different.  Being members of the grunt family, they also “croak” like croakers and drums – hence their common name “pigfish” – due to the grunting sounds.  This helps with identifying which fish you have.  Though common in the grasses, I did not catch these as frequently as pinfish and they were not as abundant. 

Spotfin Mojarra

This is a common silver baitfish that resembles the pinfish and is frequently collected in our seine nets.  The mojarra is in a different family than pinfish.  They lack sharp spines and incisor teeth, rather they have a sort of “vacuum” like mouth which they use to suck small invertebrates from the sand. 

Gag Grouper

This is a popular sport and commercial fish from the wrecks and reefs of the Gulf of Mexico.  But gags begin their lives in the seagrass beds, and we have collected medium sized individuals in our seine nets.  This underscores the importance of these grassbeds to the fisheries so many love.  We need to protect these systems from our activity both on land and in the water. 

Gag grouper. Photo: National Oceanic and Atmospheric Administration

Jacks

Another popular group with anglers, many species of jacks use these grasses as their nurseries.  We most often collected juvenile lookdowns, pompano, and crevalle in our nets.  At times we caught a small member of the family called a leatherjacket.  These were seasonal and associated with breeding.  Once again, underscoring the importance of having healthy seagrasses. 

Jacks have the sleek, fast design of the typical open water marine fish. Photo: NOAA

Toadfish

One of the creeper looking fish in the seagrass community is the Gulf toadfish (also known as the oyster dog).  This monstrous looking bottom fish lives in burrows scattered around the grassbeds where they lie in wait to ambush prey.  Their large mouths and sharp teeth can grab a variety of creatures, including the human finger.  At times small toadfish will move into an empty can or bottle discarded by people instead of a burrow where they grow to a size they can no longer escape.  It is said there may be a mild venom associated with their bite.  Though no one has ever died, or been sent to the hospital, due their bite, it is painful and should be avoided. 

The common estuarine Gulf toadfish. Photo: Flickr

Barracuda

Yes, barracuda can be found in seagrasses.  But in our case, these have all been juveniles.  There are three species of them, and they are not easy to tell apart.  They also appeared to be seasonal in our collections.  We never found them high numbers, usually one or two in a seine.  But they are present. 

The Great Barracuda. Photo: NOAA

Lizardfish

This is another medium sized, sharp toothed, bottom dwelling predator of the grassbed community.  There are seven species of them, and all have that “snake” “lizard” look to them having many sharp canine teeth.  They spend their time buried in the sand waiting to ambush potential prey.  Snorkelers may see them as they dart away tossing up sand when we get too close.  I rarely see them snorkeling but occasionally capture them in the seine net to the delight of the students assisting.  

Blennies and Gobies

These are very small fish that are almost impossible to find while snorkeling but are often collected in the seine net.  They resemble the freshwater darters and, lacking a swim bladder, spend their time on the bottom.  There are many species associated with rocks and artificial reefs but there are some who call the seagrasses home.  They use their incisor teeth to feed on small invertebrates in and on the grasses.  Being territorial, they can give a little nip to your hand.  Gobies differ from blennies in that their two pelvic fins are fused together to form a sort of “cup” or “sucker disk”. 

Puffers

Another one of the more popular fish with students who help me seine.  Everyone loves to see them inflate with either water or air into a “balloon” to make it very difficult for predators to consume them.  There are eight species of puffers in the Gulf of Mexico, five of them have been captured in our seines.  Most are small with little “bumps” on their bodies instead of spines.  But there is the Burrfish, who is a member of a different family that is medium sized, has spines, and is very common in the grassbeds.   

Striped Burrfish Photo: NOAA

Filefish

Our grassbeds are full of a small cousin to the triggerfish – the planehead filefish.  Like triggerfish, filefish have a thick sharp spine that is found at the front of the dorsal fin – called a “trigger” on the triggerfish.  The planehead filefish is a small species (nine inches average length), green to brown in color, and very common in the grassbeds; though you will probably not see one unless you catch it in a net. 

Planehead Filefish. Photo: NOAA.

Flounders and Soles

A favorite food fish for many locals, flounders spend a lot of time buried in the sand near grassbeds to ambush prey.  Born with a typical fish design, early in development one of their eyes will move to the other side of the head, giving them two eyes on one side.  By doing this, they have increased their binocular vision, improving their ability to judge accurate distance of the prey, and making hunting easier.  They lose color on the side where the eye has left and have chromatophores (cells) on the side where the eyes are that, like octopus and squid, allow them to change colors and blend in.  In our part of the Gulf, if the eyes move to the left side of the head, they are called flounders.  If they move to the right, they are called soles.  Soles in our part of the Gulf of small not of much interest to anglers.  One small species is often collected by shrimpers who feed them to hogs.  This sole can “cup” their body in defense making like a suction cup and they do this in the throat of the hogs sometimes killing them.  They are called “hogchokers”.  Flounders on the other hand are very popular with anglers.  Some fish for them using rod and reel, others prefer gigging them at night using lanterns.  There are 17 species of flounder, some reaching lengths of three feet. 

A flounder scurrying across the seafoor. Photo: NOAA

Tonguefish

Tonguefish are small flat fish with eyes on one side of their heads like flounder.  They differ than that their tails come to a point and there is no caudal fin present, as there is in flounders.  As mentioned, they are small – ranging from 3 to 8 inches in length.  The Blackcheek tonguefish is particularly common in our grassbeds.  But like so many, you will not see it unless you catch it in a net. 

Snook

This is a very popular gamefish from south Florida associated with several habitats including grassbeds.  Due to a process some call “tropicalization” – the movement of tropical species north due to climate change – snook are now, albeit in small numbers, reported in the Florida panhandle.  This is a new species you may see while exploring or fishing out there. 

This snook was captured near Cedar Key. These tropical fish are becoming more common in the northern Gulf of Mexico. Photo: UF IFAS

There are many more species of fish found in our grassbeds we could talk about, but we will end it here.  As we mentioned in the beginning, this is a group of animals that many come to the beach to find.  Whether for fun or for food, finding fish makes for a good day.  See how many different species you can find. 

A Sea of Grass Part 9 The Rays

A Sea of Grass Part 9 The Rays

As I write this article it is mid spring, and the rays are bedding on the edges of our seagrass beds.  The most common species seen is the Atlantic Stingray (Dasyatis sabina).  They are often found in the sandy areas near the grass where they bury in the sand to ambush potential prey.  This time of year, their numbers increase as the females are preparing to releasee their young in summer.  Mating occurs in early spring and the females will deliver live young1.

According to Hoese and Moore2, there are eight families and 18 species of rays and skates found in the Gulf of Mexico.  These are cartilaginous fish found in the same class as sharks but differ in that their gills slits are on the ventral side (bottom) of the body and their pectoral fins begin before the gill slits do on the side of the head.  Most are depressed (top to bottom) and appear like pancakes, but not all of them.  Sawfish and guitarfish appear more like sharks than rays. 

Of the 18 species listed, seven can be found in the estuaries and may be associated with nearby seagrass beds.  Two are species of sawfish, which are rare in our bays these days. 

The sawfish. Photo: University of Florida.

There are two members of the eagle ray family, the cownose ray and the eagle ray, which can be found in our bays.  These resemble manta rays but differ in that they lack the characteristic “horns” of the manta (often called the Devil Ray because of them) and they do possess a bard on their tail, which manta’s do not.  These are more pelagic rays spending their time swimming in the water column and hunting for buried food. 

The cownose ray is often mistaken for the manta ray. It lacks the palps (“horns”) found on the manta. Photo: Florida Sea Grant

The butterfly ray does resemble butterflies in shape having wide “wing-like” fins and a very small tail.  It behaves similar to stingrays burying in the sand and ambushing smaller prey. 

Two of the more familiar stingrays are found in our grassbeds, the Atlantic Stingray and the Southern Stingray.  The Atlantic Stingray’s disk is more round in shape while the Southern Stingray’s is more angular shaped.  The Southern Stingray is larger (disk width about five feet, Atlantic disk width is about two feet) and prefers estuaries with higher salinity.  The Atlantic Stingray is very common and can tolerate freshwater, thus is common throughout the bay. 

The Atlantic Stingray is one of the common members of the ray group who does possess a venomous spine. Photo: Florida Museum of Natural History

Stingrays are notorious for their venomous bards and painful stings.  They actually try to avoid humans and are frequently spooked by our activity fleeing as soon as they can.  However, there are times when people accidentally step on one buried in the sand, or hiding in the grass at which time they will flip their whip-like tail up and over to drive their barb into your foot forcing you to move it – and you do move it – while you yell and scream.  The ray then will swim away and can regrow a new barb. 

The bard is a modified tooth.  It is serrated on each side and there is a thin sac of venom along the flat side of the barb.  When it penetrates your foot there is pain enough there.  But the natural reaction of your body to an open wound is to close it, this reaction can pop the venom sac and release the toxin.  The chemistry of the toxin is not life threatening to humans but is very painful.  This experience is something you do want to avoid. 

Like their shark cousins, rays do have rows of small teeth which they use to crush small invertebrates including shelled mollusks.  They lie in the sand to ambush prey moving in and out of the seagrass beds.  They possess two spiracles on the top of their heads which provide water to the gills when they are lying on the seafloor or buried in it.

 Like sharks, males can be identified by the two claspers associated with the anal fin and the females usually have two uteri where the young develop.  In skates, and some other rays, the young are deposited into the environment within a hardened egg case often called a “mermaids purse”.  We see these washed ashore in the beach wrack.  Young stingrays usually develop within the female and are born “live” in summer. 

Though there is fear of this animal from some seagrass explorers they are a small threat unless you step on one.  To avoid this, when in and around the sandy areas of a grassbed, move your feet in what we call the “stingray shuffle”.  This is sliding your feet across the surface of the sand instead of stepping.  The pressure generated from this movement can be detected by the ray several feet away and they will immediately move away.

Despite the fear, they are amazing creatures and play an important role in the overall health of the grassbed community. 

References

1 Snelson, F.F., Williams-Hooper, S.E., Schmid, T.H. 1988. Reproduction and Ecology of the Atlantic Stingray, Dasyatis sabina, in Florida Coastal Lagoons. Copeia. Vol. 1988, No. 3 (Aug 1988). Pp. 729-739.

2 Hoese, H.D., Moore, R.H. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana, and Adjacent Waters. Texas A&M University Presse.  College Station TX. Pp. 327.