fish

Staff spotlight – Scott Glasmeyer

We met up with Scott Glassmeyer, a student research assistant in the Fish Division, to get an inside view on his role in the Museum of Biological Diversity.

Scott Glassmeyer holding a Rock Bass (fish)Hilary: “What is your major?”

Scott: “My major is Forestry, Fisheries, and Wildlife, with a specialization in Fisheries and Aquatic Science. I’d always loved fish since I was a kid and before I got into this program, I didn’t know that you could go to college to study fish, or do anything relevant with fish in a job, besides working to commercially collect fish. So, I did research to see if there were any higher education programs that involved learning about fish and aquatics and I found that Ohio State had this program.”

Hilary: “How long have you been a student research assistant in the Fish Division?”

Scott: “Since spring of 2016, but I started as a volunteer in January of 2016 where my primary role was to take older jars containing fish specimens and place them in new ethanol, to better preserve the fish.”

several fish in ethanol in glass jar

Fish in ethanol

Hilary:  “What is the mission of the Fish Divsion?”

Scott: “To preserve historical records of species of fish for future reference and overall long-term data collection and education. It’s a way to validate that this species of fish was recorded in a particular area and a specific species was recorded in general, as fish get misidentified a lot. So it improves a lot of accuracy regarding records.”

Hilary: “What fish are housed here?”

Scott: “Mostly Ohio fish, but we have some from the entire 50 states as well. There are also some fish species from other countries, some saltwater fish, and some aquarium fish here as well.”

Hilary: “Are the specimens here largely donated?”

Scott: “A lot of the specimens are collected through the museum, as well as the Ohio EPA. The Ohio EPA has a division that monitors streams and stream quality statewide and they will collect fish in the process and send them to us.”

collecting fish with seine nets

Staff collecting fish with seine nets

 

Hilary: “How are the fish preserved?”

Scott: “The way the preservation process works is that you put the fish specimens in formaldehyde for a certain amount of time, then you place them in water for about a day, before you start adding the ethanol bit by bit, as you slowly add larger amounts of ethanol to build up the tolerance – and that’s what they stay in. It takes up to a week and a half to two weeks to put them in this preserved state.”

Hilary: “Why is it important to study these fish?”

Scott: “It’s really important to study these fish because it helps you not only understand the water quality of their habitat, but also the intrinsic value of their ecosystems. For example, if you have a stream that’s just concrete because it was filled in, this could possibly only allow for about 5 species of fish to live there, whereas before, when the stream had natural morphological features and geological shapes, there were a lot more species of fish living within in this habitat.”

“A good example of this is from about 6 or 7 years ago, when the 5th Avenue Dam along the Olentangy River near campus was removed. Trees, plants, and wetlands were added along the bank and this natural state contributed to the value of the stream, not just for people, but for the fish as well, as this improved quality increased the level of biodiversity within in and around the river.”

Scott Glassmeyer holding Giant bottlebrush crayfish

Scott Glassmeyer holding a Giant bottlebrush crayfish

Hilary: “What’s your favorite part about working in the Fish Division?”

Scott: “I love going outside, putting waders on, getting in the stream and finding fish. You can read all you want about how healthy a stream is, but when you go out there and you see the biodiversity in the water as you collect data, you can tell just how healthy the water is and it’s wonderful.”

“I also really like the people who work here with me. Everyone’s very patient here and they take the time to help you out as your learning, which is really nice as learning to identify fish for the first time involves a learning curve.”

Hilary: “What is a project that you’re working on now?”

Scott: “I’ve been editing photographs of fish taken by Brian (my colleague who is the Sampling Coordinator in the Fish Division) and getting them ready to be put into the field guide version of the Fishes of Ohio.”

book cover Fishes of Ohio by Milton B Trautman

“The Fishes of Ohio was a guide written in the ‘50s, by Trautman, and then it was revised in the ‘80s by Trautman, and so what we’re working on now would be the next revision. There’s around 190 species or so of fish in Ohio, including invasive species and extinct species, so we’ve been photographing each species listed in the field guide, oftentimes with more than one picture, as you’re taking pictures of what you use to identify them. For example, for some of the sucker species of fish, you have to show the mouth, as that helps with identification. So with these species, there’s some photographs detailing the mouth from underneath, and there’s some side photographs, so that you can see the shape of the head and the mouth from the side for identification.”

 

Hilary: “Do you photograph the fish in their habitat?”

Scott: “It depends. There was one species of fish where we went out during their spawning season and had the tank set up to photograph them. We caught them, put them in the tank, and took a picture quickly, as they can lose their colors pretty fast. If a fish we find doesn’t have a particular color, we take them, put them in a cooler with an aerator, and take them away from location to photograph them. It’s a time consuming process, with the drive to the specimen’s location, the set-up, hours of wading for fish, and then the tear-down of equipment and the drive back from the site, so taking them away to photograph them can be easier than doing it onsite.

Hilary: “You said that fish lose their colors – what does that mean?”

Scott: “Fish have pigments in their skin, underneath their scales. There’s a lot of colorful fish in Ohio, like darters and minnows, that will have breeding colors and so, during certain times of the year and certain times of the day (or even after they eat) they’ll get a lot of pigment and colors in them. And even if they’re not a colorful fish, their colors can change. For example, you can take a large mouth bass that has some pattern to it and put it into a bucket that’s really light and pull the fish out ten minutes later, and the fish will look really pale. But if you put it in a dark cooler, the fish is going to remain dark and have more color. The stress levels will impact them.”

Hilary: “Do you have a favorite fish species?”

Scott: “This question’s hard. So, my answer changes every month when I discover a new fish, but currently my favorite fish is the Common Dolphin Fish, or the Mahi-mahi. There’s a reason why I like it: So, over 50% of its diet is flying fish, and that’s pretty cool to me. Also, its maximum life span is five years. A marlin or a swordfish can live to be about 27 years of age, and a medium sized Ohio fish species can live to about 15 years. However, the Dolphin Fish lives such a short span of time compared to these fish, yet it grows extremely quickly, as they get up to 36 pounds in 8 months. And it’s really fast too, swimming speeds up to 50 miles an hour.”

Common Dolphin Fish, or Mahi-mahi

Hilary: “With all of your experience and studies, what do you hope to do in the future?”

Scott: “I’d love to work as a fisheries biologist, working for the environment. It’s challenging to get in those types of roles, as they’re very competitive, but I’m going to try.”

 

Hilary HirtleAbout the Author: Hilary Hirtle is the Faculty Affairs Coordinator at the OSU Department of Family Medicine; her interest in natural history brings her to the museum to interview faculty and staff and use her creative writing skills to report about her experiences.

Everyday Life at the Museum-part2

Following Monday’s post, here are some illustrations of everyday life in the rest of our collections:

In the Adams lab ants are busy tending their fungi gardens. No students are working the day I stop by, but Rachelle Adams, Assistant Professor in the department of Evolution, Ecology & Organismal Biology, is happy to take a break from her computer work and she shows me the ant colonies in her lab.


In the Herbarium long-time volunteer Donna Schenk relabels some of the folders that hold the plant specimens. Taxonomy is not static, molecular studies reveal new relationships and classifications are revised. To keep the collection up-to-date and to make it easy to find each specimen we need to keep up with these changes.

In the mollusc collection I find Collection Manager Caitlin Byrne working on the computer. Student worker Trevor Smoot sorts through a bag of mussel shells which a researcher donated to the collection. With a big smile Trevor lays out the shells on top of the cabinets, apparently these are some his favorite species. Others will be identified and catalogued later.

In the fish collection Sampling Coordinator Brian Zimmerman and Assistant Curator Marc Kibbey both work on their computers.

Zoology major Elijah Williams catalogs fish specimens from a recent acquisition:

 

About the Author: Angelika Nelson is curator of the Borror Laboratory of Bioacoustics and the museum’s social media and outreach manager.

*** Do you have any questions? We would be happy to answer them ***

A time of giving – 10 million specimens

The Fish collection has undergone a dramatic growth spurt, more than doubling in size, through the gift of a collection of fishes held by Dr. Tom Simon. Our colleague served as an expert in fish and crayfish biodiversity for Indiana and taught courses on larval fish biology at OSU’s Stone Lab. The transfer of specimens was planned with Tom upon his retirement, but happened more quickly because of his sad, sudden passing.

This slideshow requires JavaScript.

The relocation of the collection was spearheaded by Division of Fishes Curator Marc Kibbey, who served as logistics coordinator  and chief box mover for our three trips to the Bloomington facility where the material had been stored. Like so much of what we do, this move depended on the help of our students, volunteers, and colleagues, who showed up over several weekends to help us move thousands of boxes of specimens.

boxes organized for pick up

The students and friends helping in Bloomington organized boxes in advance of our arrival.

The Simon collection includes a synoptic collection of Indiana fish diversity plus extensive holdings of larval freshwater fish from across the US. It also contains historical collections that had been “orphaned” when institutions closed or experts retired. Unpacking and integrating the more than 10 million specimens we have acquired through this gift will occupy us for years to come. The tasks of accessioning, rehousing, and databasing the specimens are leavened by the opportunity to see so many fish, and to find some real gems within the collection.

 

About the Author: OSU Professor Meg Daly

Dr. Meg Daly is the Director of the OSU Museum of Biological Diversity, Professor in the department of Evolution, Ecology & Organismal Biology and manages the Lab of Marine Invertebrate Diversity.

 

 

One of these skulls is not like the others

When we receive queries for identification of skulls or specimens, we turn to our large specimen collection to find those that look similar and may help in the identification process. Among other osteological features we can look at the proportions of the skull, along with the size, number and spacing of the teeth. All these features of a recently received picture of a specimen in question led me to suspect that the specimen is foreign to the Great Lakes, and based on the very small size of the specimen I suspected that it may be a Round Goby. Following I will show you some of the specimens I looked at to bolster my conclusion.

Let’s start with a picture of a Round Goby from our collection:

skull of OSUM104702 Neogobius melanostomus Round Goby

OSUM104702 Neogobius melanostomus, Round Goby

Note the width of the skull, and the abundance and spacing of the teeth on this specimen.

The species that I considered to have the skull that would most closely match the proportions of the putative goby skull was the Central Mottled Sculpin.

head of OSUM37269 Cottus bairdii Mottled Sculpin

OSUM37269 Cottus bairdii, Mottled Sculpin

 

 

 

 

 

 

 

But here you can see that the head of the Mottled Sculpin is actually wider than, and the teeth proportionally not as large as those of the Round Goby (there are several other skeletal differences but those sufficed for this diagnosis).

There are several native fish that are carnivorous and have caniniform or cardiform (small, numerous and closely spaced) teeth that I mused over, but as you can see almost all of those have much narrower skulls and/or have shorter, fewer and more widely spaced teeth than the skull in question.

This slideshow requires JavaScript.

Note: The Sauger, very close in appearance to the Walleye, was once abundant in Lake Erie but is now caught very seldom in the lake and its tributaries.

As you can see there is nothing quite like the Round Goby among our native species, and we should no doubt be thankful for that!

head of OSUM104702 Neogobius melanostomus Round Goby

OSUM104702 Neogobius melanostomus, Round Goby

Let us hope that the situation remains the same, and in the meantime, if you find a good use for these little monsters feel free to apply it and let us know your ideas.

 

About the Author: Marc Kibbey is Associate Curator of the Fish Division at the Museum of Biological Diversity.

 

What it takes to be a successful Invader

Invasive species have received a lot of bad press, but let’s face it, some of these alien species really have what it takes to make it!  One example of a highly successful invasive species is the Round Goby, a native to central Eurasia including the Black Sea and the Caspian Sea.

Male Round Goby in black spawning coloration

Male Round Goby in black spawning coloration

Identifying an alien

Recently a graduate student in Michigan sent a request for identification of a fish skull.  When I saw the skull on a photo that the student attached to the inquiry my first thought was that this is a species I haven’t seen before.  I was thinking to myself, “in my mind I’ve got a fairly good catalog of all the native species that are found in the Great Lakes, so this one is probably exotic”.  Furthermore, I examined the teeth and the rest of the skull picture, and found features that are similar to the marine blennies and gobies that I’m familiar with; quite possibly a Round Goby.

OSUM 104701, Neogobius melanostomus skull

OSUM 104701, Neogobius melanostomus skull

When one observes the teeth of a Round Goby skull, it becomes readily apparent that they are eminently suited to catching prey: numerous, closely packed and somewhat curved teeth. Once the fangs are sunk into the prey’s body it would be difficult to wriggle out of the goby’s maw.  Speaking of the “maw”, the width of the Round Goby’s head and mouth are somewhat disproportionately large in comparison to the size of the body.  This aspect of the anatomy amplifies the capacity of the fish to suck in its prey.  By opening the mouth quickly a vacuum is created, which when combined with the sudden forward lunge that the goby employs toward the prey, improves the likelihood of successful capture.

Neogobius melanostomus are extremely aggressive and will challenge fishes larger than themselves, outcompeting native fish for preferred habitat as well as preying on other fish’s eggs and young.

What makes the Round Goby so successful?

Round Gobies are found primarily in the benthic zone of the water body, from the bottom of shallow areas down to 70 feet in depth.  They prefer areas where there is plenty of cover such as around rocks, sticks and logs.  The species has been found to tolerate polluted conditions, which enables it to occupy areas that less tolerant species cannot live in. This increases their opportunities to grow into a large population that aids in overcoming the other species in less polluted areas.  Another aspect of their biology that enhances their prowess is a highly developed lateralis system, a fishes’ sensory system conveying environmental information to the brain and making them an effective competitor and predator in dark, murky conditions as well as in clear daylight.

High productivity is a hallmark of an effective invader.  A mature Round Goby female is able to produce over 3,000 eggs, the older the female the more eggs they produce.  The male uses posturing and coloration (see the photo above) to attract females to its nest, often mating with more than one female.  The females spawn up to six times in a season, which lasts all summer long from April through September. Let’s do the math: a female could produce 18,000 young in just one year, that’s a lot of Round Gobies!

Although the deleterious effects of this intruder are considerable in scope, as some research here at OSU has shown, one must nonetheless admire their capabilities.  But we should keep in mind that without our assistance it is doubtful that Round Gobies would have spread so far and certainly not so quickly.  Their ability to tolerate euryhaline conditions, a wide range of salinities, facilitates their natural spread under normal conditions over a much longer time. It has allowed them to survive in the ballast waters of vessels and occupy new areas when the ballast is flushed.

Although they are best known from the Great Lakes they are now found in the lower reaches of larger rivers and have been captured in the Illinois River drainage, presaging their invasion of other Mississippi River tributaries.

map of Round Goby invasion in Great lakes regionBut thus far the most dramatic spread of the Round Goby has occurred in the Great Lakes of North America where a lack of effective competitors facilitated their occupation of new territories.

Northern Europe, too, has suffered from a Round Goby Invasion as shown in these maps and the potential for their spread in Europe is estimated to be much greater. You can follow them on AquaMaps, enter genus “Neogobius” and species “melanostomus” to obtain a map showing their predicted spread.

map of Round Goby invasion in Europe

 

Because they are not tasty to humans it is hard to truly appreciate this fish from any perspective other than that of their successes as invaders. But to a larger, piscine predator they must indeed be tasty as they have become a substantial part of native gamefishes’ diet.  And for Lake Erie water snakes, as well as aquatic birds like gulls and cormorants, Round Gobies are a major new item on the menu.  Indeed, Round Gobies are so abundant in Lake Erie that frustrated anglers often complain that the pesky little perciforms are the only thing they can catch.

The Round Goby is here to stay, and changes wrought by their incursion will reverberate for decades across the Great Lakes at least. Have you caught one yet?

 

About the Author: Marc Kibbey is Associate Curator of the Fish Division at the Museum of Biological Diversity.

Sucker Bridgework

Comparative anatomies of skeletons stored at the OSU Museum Fish Division can be studied to reveal information on the sort of ecological niches a particular species occupies.  One example is the feeding niche that various sucker fish species exploit.  Based on structures of their throat teeth and the type of prey items retrieved from their digestive tract it would appear that buffalo and carpsucker species use their fine, comblike teeth for sieving their prey, while suckers with larger teeth (most redhorses, hogsuckers, spotted suckers) are said to “masticate” their soft prey, and finally those with the sturdiest teeth are able to shatter the hard shells of molluscs.

The photo below shows the anterior portion of a Silver Redhorse skeleton (OSUM 101341), with an arrow pointing to the pharyngeal tooth arch (position indicted by arrow) located at the rear of the gill basket.

SilverRedhorseSkeletonOSUMHeadshowingpharyngealteeth

There are  16 extant species of sucker fishes in Ohio’s waters.  Images of four of those species with pharyngeal tooth arches removed from some of our skeletons are shown below.

Spotted Sucker1 from Wolf Creek (Kankakee River) IN 07 01 07 by BZ

Spotted Sucker, Minytrema Melanops.  Photo by Brian Zimmerman.

MinytremamelanopsSpottedSuckerPharyngealTeeth

The Spotted Sucker has been reported to feed on organic fragments, diatoms, copepods, cladocerans, and midge larvae.

SmallmouthBuffalo

Smallmouth Buffalo, Ictiobus bubalus.

IctiobusbubalusSmallmouthBuffaloPharyngealTeeth

Smallmouth Buffalo suckers with their relatively delicate teeth feed on diatoms, dipteran larvae, copepods, cladocerans, ostracods, bryozoans, and incidental algae attached to bottom substrates.

ShortheadRedhorse

Shorthead Redhorse, Moxostoma macrolepidotum.  Photo by Ben Cantrell.

MoxostomamacrolepidotumShortheadRedhorsePharyngealTeeth

Shorthead Redhorse stomach contents have revealed their diet to consist primarily of midge, mayfly and caddisfly larvae.

River Rehorse from the Duck River at Shelbyville TN by Uland Thomas

River Redhorse Moxostoma carinatum.  Photo by Uland Thomas.

MoxostomacarinatumRiverRedhorsePharyngealTeeth

The River Redhorse has the sturdiest teeth of the four sucker species’ teeth shown here, so much so that they are capable of cracking the shells of bivalve molluscs and snails.

For comparison, inserted below is a photo of the molariform pharyngeal teeth from a Freshwater Drum.  The drum is primarily a carnivore, its diet comprised more extensively of bivalve mollusc and gastropod shells, while the omnivorous sucker fishes find most of their food by grazing the bottom of streams and lakes, sifting sand and gravel to find their little morsels.

drum pharyngeals downsized

 

About the Author: Marc Kibbey is Assistant Curator of the OSUM Fish Division.

Toothy Customers

OLYMPUS DIGITAL CAMERA

A frequent subject of our writings, the Bowfin

Only vertebrates have true teeth, and the type of teeth they have is indicative of the feeding niche they occupy.  Fishes portray an amazing picture of diversity in teeth and correspondent feeding niches.  Some fish species have no teeth at all and thus rely on their mouths to either crush their prey as in the sturgeon, or simply suck in their prey as in the seahorse and pipefish.  Some have very few teeth, such as the non-parasitic lampreys in adult form, and some have an absolutely terrifying array of teeth such as the pikes and the sharks.

IMG_1866[1]

Ventral, exterior view of a Northern Pike jaw

The placement (marginal, medial and pharyngeal) of teeth within a fishes’ mouth is one of the many characters that are used to differentiate fish species.  But a Northern Pike seems to have almost all the surfaces covered:

Esox masquinongy teeth

Disarticulated Northern Pike jaw.  As you might imagine, once the prey fish is caught with the canine teeth and moved into the mouth there is little chance for escape.

Piscivorous fish typically have long, sharp teeth, but some piscivores rely on strategies alternative to their dentition to capture their prey.  The billfishes (marlins, sailfishes and swordfishes) stab and stun their prey with their elongated rostrums, sawfishes slash with a many-toothed rostrum to “collect” their prey.  Electric eels stun prey fishes, while toadfishes, anglerfishes and batfishes use a lure on their snouts or at the end of an extension to attract small fishes and may include a pheromonal attractant.  Such species typically have numerous smaller rows of teeth to grasp and hold their victims.

Fishes also exhibit diversity in the attachment of the teeth in their jaws:  The “Type I” arrangement has a strong mineralized connection between the tooth and and the jaw in bichirs, gars, bowfin, lower teleosts and some higher fishes (or the tooth and the pharyngeal bone in paddlefishes).  The “Type II” arrangement is seen in many teleosts with mineralization incomplete and the tooth connected to the jaw by collagen.  Stomiiformes (the order in which such bizarre, deep sea creatures as dragonfish, marine hatchetfish and viperfish are placed) have the Type III attachment with teeth hinged and depressible for moving prey to the esophagus and then erectible to prevent prey from escaping.  The Type IV attachment has collagen at the posterior part of the tooth base and acts as the hinge with the anterior edge lifting off the base (exposing the pulp cavity) to trap prey, this arrangement is found in pikes, some stomiiforms and higher teleosts.

Some fish groups such as sharks, wrasses, filefishes and triggerfishes exhibit polyphyodontia, the lifelong replacement of teeth.  A new tooth develops in the dental lamina under or behind the existing teeth.  In the sharks, for example, only the front 1 or 2 rows are used for feeding, while teeth develop posteriorly and move anteriorly to replace teeth individually as needed and on a regular basis.  In some shark species this occurs as frequently as every 9-12 days in the sandbar sharks or as infrequently as two to four times a year in the blue shark; with the old teeth drop to the ocean floor.  Exceptions include some like the cookie cutter sharks where the entire upper and lower sets are replaced as units and swallowed.  Piranhas replace one entire side of the teeth on their jaws at one time.  Polyphyodontia is a character that is not unique to fish however; a few mammals (kangaroos, elephants and manatees) and several reptiles replace their teeth too.  Many bony fish are monophydontic and develop only one set of teeth, while most mammals are diphydontic, replacing their teeth only once.

Below are several examples of fish groups or individual species that exemplify the variety in fish dentition and coincident feeding niches.  Forthcoming at the end of the week I’ll post images of these species and their teeth.

Lampreys – start out their life cycle with a toothless mouth suited to filter feeding, and in the parasitic forms develop several circular rows of sharp teeth used for latching onto and rasping a hole in their prey.

Sharks– teeth are triangular and razor sharp, those on the lower jaw have small serrated lateral cusps at the bases for enhanced cutting and tearing that is facilitated with strong jaw musculature and shaking motion of the head or chewing.  Sharks, unlike the higher fishes, do not have pharyngeal jaws associated with their gill baskets.

Lungfish – have a tooth structure unique among the vertebrates: sturdy tooth plates called “Odontodes” that are used for grasping and crushing prey

Gar – rows of small villiform teeth for capturing and holding fishes in their elongated jaws while they manipulate the fish to a headfirst position for swallowing

Bowfin – many sharp caniform, inward pointing teeth on the premaxilla, dentary and maxilla jaw bones for grasping and holding the prey (an extreme example of canine teeth is shown in the African Tigerfish)

Pike – the long, sharply curved caniform teeth on the dentary are a prelude to a villainous array of cardiform teeth  on the premaxillary, basibranchials, last two pharygobranchials, vomer, palatines, and glossohyal bones.

Grass Carp – the heavy pharyngeal teeth of these herbivores are used for shredding algae

Piranha  – teeth are triangular, razor sharp, with small lateral cusps at the bases like sharks

River Redhorse – feed on sand-dwelling mollusks with sturdy teeth on lower pharyngeal jaws (characteristic of all ostariophysans whereas higher teleosts have pharyngeal teeth on lower and upper arches like the redear sunfish) used for crushing molluscs found in the bottom substrates

Flathead Catfish – gulp prey with large, non-protrusible mouth and hold with cardiform teeth, the largest patches of which are on the premaxillary and anteior dentary bones

Largemouth Bass – have limited cardiform teeth on the medial jaw bones, but these are complimented by a large, protrusible mouth for engulfing prey

Ocean Pout – like many molluscivores have strong conical dentition on the anterior portion of their jaws for plucking mollusks from surfaces, and flattened, molariform teeth in marginal or pharyngeal jaws

Triggerfish (incisor-like dentition), Pufferfishes (teeth fused into parrotlike beak) – have powerful oral jaws to remove invertebrate prey (sponges, ascidians, coelenterates and chitons) from surfaces

 

About the Author: Marc Kibbey is Assistant Curator of the OSU Fish Division at the Museum of Biological Diversity.

 

Madtoms of the OSUM Fish Division

 

Why are the ‘toms mad?  Might have to do with the fact that madtoms are so small and have a hard time competing with their larger con-familials (like Bullhead Catfish and Channel Catfish) for space and food.  But connate with several other small animal species they make up for their small size with a nastily painful poison sting.  Ask any catfish aficionado, or even a neophyte; and they will tell you that they pay careful attention to the sharp spines the catfishes carry at the front of their dorsal and pectoral fins.  Whereas catfishes of the North American Ictaluridae genera other than Noturus lack the actual venom, those other genera do carry bacteria on their spines that can cause infection in the wound. The madtoms secrete their venom in a sac at the base of their pectoral spine.  When threatened the madtoms lock their pectoral spine in an erect position, causing the sac to rupture and releasing the toxin into the water.

Another character that typifies smaller animals is their habit of remaining in the shadows.  Madtom species are quite furtive, hiding under rocks and logs or in crevices including crayfish burrows.   Like other catfish genera they tend to be most active at night.  A savvy madtom collector sallies forth in the darkness with a lantern that attracts the bewhiskered nocturnals like moths to a flame.  The best time for collecting many madtom species is in the cooler months of Autumn, up through December, when they congregate en-masse out in the open.  Madtoms spawn in late spring through summer, so could it be they carry out this excursion in the colder season for the simple reason that many larger predators have moved downstream to deeper waters?

This highly cryptic group of catfishes contains several species with populations that are imperiled to varying degrees.  Some, like Ohio’s Scioto Madtom, are Extinct while many are Endangered, Threatened or Of Special Concern at the State to Federal level.  Noturus species occupy a wide array of habitats but all rely on aquatic insects for their food.  Images of a few of the madtom species vouchered in the OSUM Fish Division are posted below.

OSUM 35531 Noturus flavipinnis 1 of 1 left lateral no label

OSUM 35531 Noturus flavipinnis Yellowfin Madtom.  Several populations of this species are imperiled or extirpated.  Listed as Federally Threatened.  They were successfully reintroduced by Conservation Fisheries International in Tennessee.

OSUM 61379 Noturus munitus 1 of 90 right lateral 3

OSUM 61379 Noturus munitus Frecklebelly Madtom.  Uncommon, declining in some areas of five small, disjunct populations in Gulf Coast drainages.

Noturus flavus 103721

OSUM 103721 Noturus flavus  The Stonecat Madtom is one of the most abundant, as well as the largest madtom species in Ohio with populations across the Mississippi River and Great Lakes drainages in the U.S. and lower Canada, frequently found in faster flowing riffles but also in lakes where there is at least a moderate current.

Stonecat by UT

Noturus flavus Stonecat Madtom, photo by Uland Thomas.

Noturus insignis 50143

OSUM 50143 Noturus insignis Margined Madtom.  Another widespread species with strong populations throughout the Atlantic Slope drainages in northeastern U.S.

Margined Madtom from the Blackwater River Roanoke Drainage VA 15JUL09 by BZ

Noturus insignis Margined Madtom from Blackwater River Virginia, photo by Brian Zimmerman.

Mountain Matom from the Little Miami by UT

Noturus eleutherus Mountain Madtom, photo by Uland Thomas.  Common in some areas but one of Ohio’s State Endangered madtom species.

Noturus miurus 86131

OSUM 86131 Noturus miurus Brindled Madtom.  Relatively common as madtoms go, prefers better oxygenated waters in streams with gravel or sand, likes to hide in leaves and sticks, also inhabits rocky lakeshores.

OLYMPUS DIGITAL CAMERA

Noturus miurus Brindled Madtom about to be released/reintroduced from my hand after a trip to Leading Creek in a cooler.

Tadpole Madtom2 from the Maumee River April 2007 by BZ

Noturus gyrinus Tadpole Madtom, photo by Brian Zimmerman.  The Tadpole Madtom occupies quieter waters with sticks and other woody debris, and tolerates muddy, silty areas better than most other madtoms.

Elegant Madtom Noturus elegans from Kentucky photo by Ben Arthur

Noturus elegans Elegant Madtom, from Russel Creek Kentucky.  Photo by Ben Arthur.  Locally common albeit only found in the Green River drainage of Kentucky.  Note the sharp barbs on the rear of the pectoral fin spine that make it particularly hard to remove catfishes from a net!

 

About the Author: Marc Kibbey is Assistant Curator of the OSU Fish Division at the Museum of Biological Diversity.

A State Treasure: Gone But Not Forgotten

Although Ohio has some 180 freshwater fish species living in the State’s lakes and streams, it is home to only one endemic species:  the Scioto Madtom, Noturus trautmani.

In November of 1943, when OSU Museum of Zoology Curator Milton Trautman captured the little catfish from his favorite locality, he recognized that it was not a form that he’d encountered during his multitudinous collecting trips.

OSUM 5914 Noturus trautmani right lateral 3 no label

 

OSUM 5914 – Noturus trautmani

 

These fish, which were later described and named in his honor, are similar to the Elegant Madtom, Noturus elegans.  A study carried out by W. Ralph Taylor (1969) recognized those similarities in describing the Scioto Madtom and placing it close to the Elegant Madtom phylogenetically (substantiated in a 2009 publication by Egge and Simons), although osteologically the two are quite different.  Icthyologists postulate that the Scioto Madtom may have speciated from an elegans population following a glaciation event.

OSUM 9575 Noturus trautmani C&S 1 with arrows pointing to anterior pectoral spine and humeral process

 

 

OSUM 9575 – Noturus trautmani – Cleared and Stained preparation.

 

 

 

Note arrows showing anterior pectoral fin spines and humeral process significantly shorter than those characters on the Noturus elegans specimen below (vertebral counts also separate the two species)

OSUM 18913 Noturus elegans head and trucnk C&S microscope shot with arrows pointing to anterior pectoral spines and humeral process

 

 

OSUM 18913 – Noturus elegans – Cleared and Stained preparation.

 

 

Although anatomical features and a unique color pattern were used to justify recognizing the Scioto madtom as a distinct species, several local fish enthusiasts have wondered whether the Scioto Madtom population were simply hybrids between the Stonecat Madtom Noturus flavus, which resembles the Scioto Madtom in coloration and in possessing a low adipose fin, and Noturus stigmosus, which has long pectoral barbs and humeral processes but strong saddle markings on its body. However, no instance of hybridization between these species has been reported, although other hybridizations are reported among madtoms.

The length of Big Darby Creek from which Milton captured almost all of what was later called the Scioto Madtom are recorded in our catalog book as 100-200’ above the State Route 104 bridge.  The first Scioto Madtom specimens collected were found in Riffle No. 3 of a series of four riffles and runs called “Trautman’s Riffle”.

Scan of drawing of Trautmans Riffle from Ohio Conservation Bulletin 1963

 

Drawing of Trautman’s Riffle from Gilfillan, Merrill C.  1963.  The Fishes of Trautman’s Riffle.  Ohio Conservation Bulletin, Vol. 27, No. 5.  pp. 22-24.

 

20140711BigDarbyCkRM3_4Trautmansriffle photo by Anthony Sasson

 

Trautman’s Riffle on Big Darby Creek upstream of State Route 104. Photo by Anthony Sasson of The Nature Conservancy.

 

 

Trautman and his successor in the OSUM Fish division, Ted Cavender, both searched extensively for populations of Scioto Madtoms outside of the type locality. These collections led to the discovery of other species of madtoms, but failed to unearth another population of Scioto Madtoms (the last one collected was in Autumn of 1957).

My introduction to Trautman’s Riffle didn’t happen until the mid-1990’s.  Although I’d spent many a day on lakes, reservoirs and rivers fishing with my grandfathers, my fishing experiences had not included seining until I took Ichthyology at OSU with Ted Cavender.

SciotoRiveratCirclevilleRiffle202EEOB626RobGaebelTedCavenderMikeSovicBenRichLeeKittle

 

Ted Cavender (center), OSUM Curator 1970-2005, with his OSU Biology of Fishes class at the Scioto River fishing access just east of the Big Darby Creek confluence, ca. 2002.

 

In the 20 years since this introduction, I have personally observed some of the riffles in the vicinity of Trautman’s Riffle moving, due to the “flashy” flooding character of the stream.  One such riffle downstream from Trautman’s Riffle headed up under the State Route 104 bridge to about 50 yards downstream, and some of the structure appears to have moved down to an area at the next major bend in the stream’s course.  Despite the dynamism of the Big Darby in this stretch, Trautman’s Riffle remains mostly intact, although it seems to have been better defined when Milton collected the Scioto Madtom back in the 1940’s and 1950’s.

The increased propensity for flooding and the increased impact of these floods in Big Darby Creek is due at least in part to anthropogenic changes to the topography of the watershed as well as to its hydrology.  Clearing of the riparian area right up to the edge of the creek removes the trees, brush and grasses that serve as a natural filter for pollutants like smothering silt loads from farm field tillage and removes tree roots that hold the upper layer of dirt and enable the stream to create undercut areas where fish hide.  A natural riparian buffer also furnishes woody debris that falls into the stream, creating more habitat and egg laying areas for fish.

Could a flooding event, other weather conditions, or impacts such as siltation of substrates from agricultural tillage, have affected the Scioto Madtom population severely enough that they were unable to propagate?  A catastrophic release of silage on Little Darby Creek in the 1980’s wiped out an otherwise healthy population of Least brook lampreys at Mechanicsburg Ohio, demonstrating the potential impact of a rare event.

Since the Scioto Madtom was only ever found in a very small population, and subsequently not found for many years, the species was listed for decades as an endangered species. Several governmental and private monitoring agencies have sampled the site and conducted exhaustive sampling of other localities in the Scioto River and other major Ohio River tributaries, especially those that focused exclusively on habitats where Madtoms could be expected.  One such effort was funded by the U.S. Fish and Wildlife Service. The 3-year project to sample the major Ohio River tributaries within the state for Madtoms turned up nets full of Northern Madtoms, Mountain Madtoms and Stonecat Madtoms, but unfortunately no Scioto Madtoms.  Because of the lack of results despite intensive expert searches, many suspected it was extinct. The U.S. Fish and Wildlife Service and the Ohio Division of Wildlife concur, and have recently declared the Scioto Madtom extinct. This new listing notwithstanding, we can’t help but keep an eye out every time we are in suitable habitat for the elusive, endemic, endangered Scioto Madtom.

 

About the Author: Marc Kibbey is Assistant Curator of the OSU Fish Division at the Museum of Biological Diversity.

Fish Face

 

Although any individual fish might be hard to pick out of its school photo,  fish faces can be  remarkably distinct.

 

About the Authors: This blog post is a collaboration between Dr. Meg Daly, Director of the Fish Division & Marc Kibbey, Associate Curator of the Fish Division.  All photos by Marc Kibbey.