July | 2016 | OSU Bio Museum

Show stoppers

July 29 2016July 20, 2016

The specimen digitization project that we are about to start at the Triplehorn Insect Collection will create a large body of information about butterflies. Those data, combined with the data from all the collections that are part of LepNet, will be a monumental resource for scientific research. The information on the specimen labels and the images of selected specimens will be fully available online and accessible to all interested parties, from scientists to government agencies to 4-H programs to school classes to the general insect-loving public.

Ohio State has never been a powerhouse of butterfly research, nevertheless we hold a very interesting collection of these fascinating insects. For example, we have some butterfly specimens that were collected in 1880s (they are as old as the Statue of Liberty!). Some of our specimens were collected in natural habitats that are now gone, completely modified by human activity. We have representatives of rare and endangered species. The Parshall donation added depth and breadth to our collection. What amazing new knowledge will we gain from accessing all those data together? The next months and years will be interesting ones!

While we wait for the data, we can enjoy the beauty of the specimens in the collection.

Moths in the Triplehorn collection

Butterflies collected long ago, but pinned only recently

Butterflies in the Parshall collection

Tiny blue butterflies

Butterflies to be mounted

Oeneis chryxus from the Yukon Territory

Saturniidae moths

Butterflies in the Triplehorn collection

Sulphur butterflies in the parshall collection

Dogface butterflies in the Parshall collection

Butterflies to be mounted

Detail of the wing of Saturniidae moths

Peacock butterflies recently pinned

Butterflies in the Parshall collection

About the Author: Luciana Musetti is an Entomologist and the Curator of the Triplehorn Insect Collection. Photos by the author.

Butterflies going digital

July 25 2016August 8, 2016

Last year the Triplehorn Insect Collection received a large donation of butterflies from Mr. David Parshall. More than 50,000 pinned specimens, and many thousands more in paper envelopes. You might have read about it on the Pinning Block (here and here.) We have also posted some photos of the collection move on Twitter.

We have specimens of all insect orders and from all regions of the world, but because we never had a faculty or staff who specialized on Lepidoptera, our moth and butterfly collection was not nearly as big as, for example, our beetle or leafhopper collections. This has changed with the addition of the massive Parshall donation.

Afrodite fritillary, <i>Speyeria aphrodite</i>, dorsal view.

Aphrodite fritillary, Speyeria aphrodite, dorsal view.

Afrodite fritillary, <i>Speyeria aphrodite</i>, ventral view.

Aphrodite fritillary, Speyeria aphrodite, ventral view.

The Parshall collection is a complete collection of the butterfly and skipper species found in the state of Ohio. It really stands out, though, because it also contains a huge number of specimens collected in the Arctic Canada and Alaska. (Imagine chasing butterflies in Churchill, Manitoba with the very real threat of polar bears around you! Makes the butterfly hunt just a little more interesting, don’t you think?)

Limenitis, admiral butterflies.

The National Science Foundation has recently funded a large project called the “Lepidoptera of North America Network” (LepNet). This project, which just began this month, is a collaborative effort of 29 institutions across the United States with the goal of making 2.1 million butterfly specimen records freely available on the Internet. If that were not enough, LepNet also aims to produce over 95,000 images of the moth and butterfly species that these data refer to. The project is being coordinated by Northern Arizona University, and the Triplehorn Insect Collection will participate through a subcontract to “digitize” the Parshall collection.

Digitization, for us, means capturing and storing the information contained on each specimen label and storing it in our xBio:D database. And from there, to the world!

Every specimen in a collection has (or should have!) a label with information on where it was captured, when, and by whom. Often we find additional biological data on the labels, like the host plant that an insect was feeding on, the habitat in which it was collected, or the method by which it was collected.

Lycaenidae butterflies showing specimen labels.

Taken together, all of these bits of information tell us a lot about the geographic distribution of species going as far back as the late 19th Century, the flight period of the adults, and much more. We have not even scratched the surface of all the knowledge we can obtain from biological collections. On July 13th a story was published in the New York Times about a team of ecologists using these same data for plants to find out how many different tree species exist in the Amazon Forest (the researchers found over 11,000!).

Digitization can also mean taking pictures of the specimens. But with millions of butterfly specimens in collections we cannot reasonably take and store several pictures of each and every one of them. So the goal of LepNet is smaller, but 95,000 is still a big number.

The Triplehorn collection’s own contribution to LepNet is more modest, but important nevertheless. The Parshall collection’s strength in Arctic butterflies is particularly interesting and even before we had fully unpacked the collection after the move the specimens were already being used by scientists (see Warren et. al., 2016).

In an era of climate change, knowing where those butterflies used to be found in years and decades past will give a good impression of the impact of environmental change.

Drawer full of colorful Lycaenidae butterflies.

Reference:

Warren, Andrew D.; Nakahara, Shinichi; Lukhtanov, Vladimir A.; Daly, Kathryn M.; Ferris, Clifford D.; Grishin, Nick V.; Cesanek, Martin; Pelham, Jonathan P. 2016. A new species of Oeneis from Alaska, United States, with notes on the Oeneis chryxuscomplex (Lepidoptera: Nymphalidae: Satyrinae). The Journal of Research on the Lepidoptera (The Lepidoptera Research Foundation, Inc.) 49: 1–20

About the Author: Luciana Musetti is an Entomologist and Curator of the Triplehorn Insect Collection.

Detective Work and Rare Collections II

July 22 2016July 21, 2016

Continued …

What did the once hidden collections contain?

The Hildreth Collection contained a total of 84 different species of freshwater molluscs, 64 of which were from the Ohio River System, 12 from other river systems, and 8 specimens from other places around the globe such as France.

The original shipping label for the Hildreth and Holden collections as sent to Dr. David H. Stansbery, emeritus Curator of Molluscs, from H.R. Eggleston.

In 1828, Hildreth published his Observations on, and Descriptions of the Shells found in the Waters of the Muskingum River, Little Muskingum and Duck Creek in the vicinity of Marietta in the American Journal of Science Vol. XIV, 1828. In it Hildreth wrote about the abundance and distribution of twenty-six species of the molluscs found in Marietta Ohio. Luckily some of the text clearly references parts of his actual collection, and it was possible to figure out the original shell’s location by comparing the two.

The most interesting part of Hildreth’s 1828 publication is where he wrote about a species called Dysnomia foliata, now known as Epioblasma flexuosa. This particular species, according to the notes and letters he left behind (as well as the many specimens he sent to other collections all over the USA), was relatively abundant. It is now extinct and no one has seen it since around 1900. How did something once so abundant disappear? Maybe someone will eventually figure it out…

How do we know when the specimens were collected?

As Hildreth added specimens to the collection, he recorded the scientific names for each of them. Scientific names often change over time as new taxonomic research is done and new methods become available. Thus a particular scientific name for a species can be used as a time stamp and, in this case, allowed us to estimate a date range for collection.

One of the papers left behind by Dr. David H. Stansbery regarding his study of the collection. This is his tally of the dates that species names were being used.

When all the names in the Hildreth collection where tallied up by Dr. David H. Stansbery, emeritus Curator of Molluscs, the story became clearer: The absolute most recent name, Quadrula fragosa, was from 1835. It is, therefore, likely that the collection itself ends a few years after that. My best guess, after going through the Marietta College database of his collected correspondence, is that the collection was set aside in 1840. That is the date when his letters stop mentioning shell exchanges and instead start focusing on geological coal surveys. I also found the first mention of a shell exchange in a letter in 1824. This indicates that, to the best of our current knowledge, the collection was made over a time-span of around 15 years.

The Holden Collection was the smaller collection of the two, made by a Mr. William Holden. It consists of either one or a few collection events from the Ohio River at Marietta in the year 1879. The Holden collection, therefore, constitutes a very rare look at the nature of the Ohio River naiad (freshwater mussel) fauna of that region between the time of Dr. Samuel P. Hildreth (1825-1840) and the time of Dr. Arnold E. Ortmann (1900-1927).

A letter from 1977 found among the documentation relating to the collections.

Ortmann, in his monograph on the Naiads of Pennsylvania, lists records of all Ohio River species of Pennsylvania present in the Carnegie Museum, but does not seem aware of the existence of the Holden Collection. This makes sense, if the collection had been sealed up in a wall between that time and WWII when it was finally discovered.

It does certainly look like this collection’s story has been told before, but unfortunately everyone I tried to track down in reference to it has long since passed away.

About the author: Sara Klips is still the Mussel Fairy and wishes more people realized how engaging shell bound mollusks can be. She hopes that you know that the “eye stalks” on slugs are called tentacles, and that you realize that filmy plastics can never be put in the recycling bin.

Detective Work and Historical Collections

July 18 2016July 15, 2016

One of the big challenges of freshwater natural history is that it is hard to determine what exact animals were present in rivers before modern collections began. Preservation of pristine freshwater environments has been almost impossible as anything upstream affects everything downstream. Our zoological museums are a physical catalogue of the historical wildlife in an area and a guide for where our habitat reconstruction goals should be set.

Physical collections are fragile. It’s easy to lose data somewhere along the line and have the specimens themselves become nothing more than physical curiosities. It’s even easier to have an extensive and meticulous collection fall into the hands of disinterested heirs and be lost to us. Specimens need to be cared for properly to maintain their quality, and the longer it has been since they were collected, the less likely it is that the historical value is maintained. Occasionally these collections are saved via thoughtful preservation by some concerned individual or institution or, much less often, by a fortuitous fluke of storage through a period when, had it been accessible, it might well have been destroyed.

A collection of old labels, now dissociated from their original specimen.

A perfect example of this kind of fortuitous preservation is represented by two collections, The Hildreth and Holden Collections, currently located in our Bivalve Collection. These two collections were discovered together at Marietta College, Ohio. Few details exist today regarding the exact discovery, but some information has been preserved. Everyone directly involved with the discovery has, as far as I can tell, passed away long ago without publishing the details of the find.

It’s a weird twisting tale and, I believe, it deserves to be informally recorded here.

Our next post will fully detail the relevance of this collection and its history, but for now let’s just set the scene…

Continue reading Detective Work and Historical Collections →

Am I or Am I Not a Dinosaur? Skull Identification Quiz

July 15 2016July 15, 2016

Do you love dinosaurs? Many of us grew up in the shadow of Jurassic Park Mania, and went through a dino-crazed phase during our childhood. Still, can you identify a dinosaur when you see one? There seems to be a lack of public awareness of what is actually classified under the label of Dinosauria.

Test your knowledge with this tetrapod skull ID quiz and check your answers below. The truth may surprise you! We would love to get comments from you. Which of these skulls is the most challenging?

1. Dinosaur or not a dinosaur?

2. Dinosaur or not a dinosaur?

3. Dinosaur or not a dinosaur?

4. Dinosaur or not a dinosaur?

5. Dinosaur or not a dinosaur?

6. Dinosaur or not a dinosaur?

7. Dinosaur or not a dinosaur?

8. Dinosaur or not a dinosaur?

9. And finally, dinosaur or not a dinosaur?

(all photos are by G Terrell 2016)

Answers

1) Yes! This is the skull of Herrerasaurus ischigualastensis. Herrerasaurus was an early theropod dinosaur from the late Triassic period, and one of the first predatory dinosaurs. (Image Credit: http://images4.fanpop.com/image/photos/22200000/Herrerasaurus-dinosaurs-22232913-1438-588.jpg)

2) No! This meter-long skull is from the living crocodilian, Gavialis gangeticus, or gharial. Gharials can be easily distinguished from crocodiles and alligators by their incredibly thin jaws, which are an adaptation for catching fish.

(Image credit: https://en.wikipedia.org/wiki/Gharial#/media/File:Gharial_san_diego.jpg)

3) Yes! This skull is from the Keel-billed Toucan (Ramphastos sulfuratus), a colorful Latin American member of the toucan family Ramphastidae. Living birds comprise the only extant members of the dinosaur family tree. Dinosaurs are not really extinct at all, there are approximately 10,000 species of living birds. Keel-billed Toucans may seem to have cumbersome bills, but they are surprisingly lightweight and useful for thermoregulation.

The closely related Chestnut-mandibled Toucan Ramphastos swainsonii (Credit: G. Terrell 2016)

4) No! This skull belongs to the early synapsid of the Permian period, Dimetrodon. Dimetrodon is often (mistakenly) labeled as a dinosaur in the popular media. In fact, Dimetrodon is a member of the lineage that eventually lead to mammals. So, as mammals, we humans are far closer relatives of Dimetrodon, than Dimetrodon is of any dinosaur.

(Image credit: https://commons.wikimedia.org/wiki/File:Dimetrodon_grandis.jpg)

5) Yes! This skull is from the late Jurassic dinosaur, Archaeopteryx . Often recognized as the “first bird,” Archaeopteryx was actually just one of many feathered, fluffy, winged dinosaurs that flitted around the forests of the Jurassic. Though probably not as well as modern birds, it is thought that Archaeopteryx was capable of briefly-sustained flight.

(Image credit: https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Archaeopteryx_lithographica_by_durbed.jpg/1280px-Archaeopteryx_lithographica_by_durbed.jpg)

6) No! This is the skull of the rhinoceros iguana (Cyclura cornuta), a species of lizard in the family Iguanidae. Rhinoceros iguanas live on the island of Hispaniola, where they can reach up to 54 inches in length.

(Image Credit: https://en.wikipedia.org/wiki/Rhinoceros_iguana#/media/File:RhinoIguanaMay07Pedernales.jpg)

7) No! This skull is the skull of a Komodo dragon, Varanus komodoensis, a species of lizard in the monitor lizard family Varanidae. Komodo dragons are the largest living lizards. They reach lengths of up to 10 feet! These large lizards have been known to prey upon water buffaloes.

(Image source: https://en.wikipedia.org/wiki/Komodo_dragon#/media/File:Komodo_dragon_(Varanus_komodoensis).jpg)

8) Yes! This is the skull of the Great Hornbill, Buceros bicornis. Great hornbills are large, mostly frugivorous birds of South Asia in the family Bucerotidae. Like many extinct dinosaurs, hornbills possess seemingly-bizarre head ornamentation that is only present in adult individuals.

(Image credit: https://en.wikipedia.org/wiki/Great_hornbill#/media/File:Great-Hornbill.jpg)

9) Yes! This skull belongs to the famous Velociraptor mongoliensis. This late cretaceous predator, made famous by the Jurassic Park franchise, was a member of the Dromaeosauridae. This family of dinosaurs is extremely closely related to birds. All members of this family were fully feathered, possessed wings, and would have appeared to be “weird birds with teeth and tails.”

(A Velociraptor with prey. Image source: https://en.wikipedia.org/wiki/Velociraptor#/media/File:Velociraptor_restraining_an_oviraptorosaur_by_durbed.jpg)

About The Author: Grant Terrell is a second year student in Evolution and Ecology at The Ohio State University. He works as a research assistant in the Tetrapod Collection at The Museum of Biological Diversity.

Vertebrates in Bits and Pieces: Space Conservation in Vertebrate Collections

July 11 2016July 11, 2016

Bird specimens that are part of the Tetrapod collection

When you picture a vertebrate collection, you probably think of a collection of taxidermied birds and mammals or jars of pickled fish. But when you actually visit the collection, you will find the typical research study skins, and pelts and – out of necessity- preserved parts of specimens such as jars with tongues, eyes, stomach contents, brains, boxes of horns, eggs, nests, wings etc. These are organized as sub-collections within a vertebrate collection and are known under varying names such as the osteological or oological collections. These “sub-collections” can be used as educational tools, in research projects, or in art classes. But when we salvage or collect a specimen, why don’t we keep the entire specimen? One may argue that a whole specimen would have higher value to a researcher than the bits and pieces found in these sub-collections.

Indeed it is useful to preserve the entire specimen but there are many constraints that vertebrate and other museum collections face that prevent us from keeping an intact specimen.

One big issue museums face is space. For vertebrate collections, though it would be lovely to

A walrus as a whole specimen takes up a large space but when folded up it can fit in a cabinet. (S. Malinich, 2013)

have an entire whale or elephant in the collection, such a specimen would take up a large part of our collection area. If a museum has a whale in its collection it may only keep parts that researchers have requested in the past such as particular vertebrae, a manus, or a partial skull. A great example of this can be found in the AudioVision “Whale Warehouse” video episode. Within the episode, Grant Slater and Mae Ryan, producers for Southern California public radio, explore the L. A. Natural History Museum’s over-sized specimen storage facility, a place where curators store parts of large aquatic mammal specimens. Not only are the specimen parts inside large but they take up an entire warehouse off grounds from the main facility!

Larger birds, such as these Golden Eagles, take up space where hundreds of smaller song birds could fit. (S. Malinich, 2013)

Here at the Museum of Biological Diversity, we do not face the challenge of storing whales, but smaller specimens in large numbers can soon turn into a space problem, too. Over 20 swan specimens, can take up the same cabinet that could be holding over a thousand smaller song birds. This puts constraints on how many specimens of a species we can accession per year and the maximum size of specimens that we can accept.

Another problem museum collections face is the condition of a specimen. Upon receiving specimens we conduct quality checks on varying aspects of the specimen.

Smelling a specimen before preparing it can save a lot of decision making it it smells rotten.

Smelling a specimen before preparing it can help make decisions if it smells rotten.

First, we conduct a sniff check: if the specimen smells rotten, it is past the point of return and we do not attempt to make it into a study skin, because it would continue to decay at a rapid pace.

A student prepares a specimen skin. While she prepares she looks it over for any reasons why it could not be made into a full study skin.

A student prepares a specimen skin. While she prepares it she checks it for any reasons why it could not be made into a full study skin.

Second, we do a visual look over on the outside of the specimen: We look for maggots, large wounds, as well as gangrenous flesh which would prevent us from turning the specimen into a whole study skin.

Third, we consider acceptance of certain specimens over the year. Though

Examining a large Great Horned Owl before making it into a parts specimen.

Examining a large Great Horned Owl before salvaging parts of this specimen.

it would be nice to make every specimen we receive into a study skin, we simply cannot fit them all into cabinets. So only the specimens that are clean (or cleanable) and not losing feathers or fur will be preserved as full skins.

Sub-collections may arise because of a researcher’s fascination with a particular feature of a specimen, but they have become important parts of modern collections. Some sub-collections of the Tetrapod Collection are: skeletons, wings, feet, tails or samples of feathers. This way important research material is preserved, but instead of taking up a large portion of a cabinet these specimens can be filed just like documents into filing cabinets. This also makes sure that valuable records of species are kept even though a full skin could not be made because of how they were found when salvaged. These parts collections can still be valuable for research, for example, when scientists need DNA samples of a particular species. New molecular techniques allow extracting DNA from small tissue samples. To make up for the loss of a full skin, we take multiple images and measurements during processing to accompany the specimen in the collection.

A typical set up for preparing study skins.

Though it would be ideal for museum’s to preserve an entire specimen it may not be possible in the future as museum collections continue to grow. However as science progresses we are finding that even the smallests amounts of tissue samples of specimens can reveal much about a species. Entire collections of just tissue samples are being formed all around the world focusing on specific taxons or groups of species. In the future, as collections continue to grow it will become more beneficial to create more sub-collections with tissue samples to further the research value of museum collections.

About the author: Stephanie Malinich manages the tetrapods collection at the MBD.

Puffin time on Eastern Egg Rock

July 8 2016June 3, 2016

Have you heard of the Atlantic Puffin, a species of seabird in the auk family? It is the only puffin native to the Atlantic Ocean.

Two Atlantic Puffins on Eastern Egg Rock

Atlantic Puffin on Eastern Egg Rock

I have been lucky to see this bird on both, the eastern and western coast of its breeding range. In 1996 when I studied at Bangor University in Wales, UK I first encountered Atlantic Puffins off-shore from Puffin Island, an uninhabited island off the eastern tip of Anglesey, Wales. The island, as you may have guessed, was named after a breeding colony of Atlantic Puffins. Unfortunately puffins no longer breed on this island after the introduction of a fierce predator of eggs and chicks, the brown rat. On the other side of the Atlantic Oceans puffins faced similar problems, they were extirpated from many areas by a combination of egg collection, hunting for meat and feathers, and displacement by expanding Herring and Great Black-backed Gull populations. Now, thanks to Dr. Stephen Kress, I have seen Atlantic Puffins off the coast of Maine, on a small island named Eastern Egg Rock.

Eastern Egg Rock is a small, treeless island in the outer Muscongus Bay area. It is designated the Allan D. Cruickshank Wildlife Sanctuary in honor of Allan Cruickshank, a Maine ornithologist and photographer.

: Eastern Egg Rock

: Allan D. Cruickshank Wildlife Sanctuary

In 2015, when I taught at one of the Hog Island Audubon camps, I was lucky to land on Eastern Egg Rock as the instructor of a group of teenagers enrolled in the Coastal Maine Bird Studies for Teens.

We landed on the island in one of the traditional fishing boats, a dory.

Access to Eastern Egg Rock is strictly limited, a small group of researchers spends the summer in the single hut on the island monitoring the numerous birds that breed on the island. Common Terns and Laughing Gulls are probably the most common species on the island that establish nests. Less common breeders are Arctic and Roseate Tern, Black Guillemots, Common Eiders and also Atlantic Puffins.

: Laughing Gull

: Common Tern

The Atlantic Puffins are a success story for conservation, the world’s first restored seabird colony. When Dr. Stephen Kress started the project in 1973 the last puffin breeding on the island had been seen in 1885. He was determined to bring a population back to this area and with the translocation of nearly 1,000 young puffins from Newfoundland, and social attraction through decoys and mirror boxes he succeeded!

Atlantic Puffin and decoy on Eastern Egg Rock

Atlantic Puffin (right) and decoy (left) on Eastern Egg Rock

The first pairs of puffins began nesting on the island in 1981, now more than 100 pairs nest regularly on Eastern Egg Rock and can be seen in the waters of near-by islands.

When we visited the island for the day, we each had the opportunity to spend some time in a small hut (bird hide) of which numerous are distributed across the island. There you sit in solitude, well hidden from the breeding birds that surround you and get to absorb views and sounds.

: view of the island with bird hide in distance

: close-up of one of the bird hides with Common Tern

I brought my recording equipment (a Audio Technica 8035 microphone connected to a Marantz PMD670) and captured the multitude of sounds:

Listen to this recording of Laughing Gulls (note the gull chicks calling in the background!):

Listen to this recording of Common Terns (also with chicks calling in the background):

It is a truly unforgettable experience to become part of this fragile ecosystem for a few hours! You can visit Eastern Egg Rock on a puffin cruise which leaves from New Harbor, ME daily during the summer months and circles the island to provide amazing views of the Atlantic Puffins and other seabirds.

About the Author: Angelika Nelson is the Curator of the Borror Laboratory of Bioacoustics and instructor of Hog Island Audubon camps.

Happy 4th of July!

July 4 2016June 22, 2016

I am currently traveling along the coast of Maine after teaching Field Ornithology and Hands-on Bird Science at the Hog island Audubon summer camp.

Don Borror, founder of the Borror Laboratory of Bioacoustics, used to teach at the same camps in the 1950s and ’60s. Like me, he recorded singing birds while identifying birds for campers. Sixty years ago to this day, on July 4th 1956, Don Borror took campers on a short boat ride to Eastern Egg Rock, one of the islands in the Muscongus Bay.

Boat ride from Hog Island to Eastern Egg Rock

This island is now famous for its Atlantic Puffins that were brought back to this area by Steve Kress through Audubon Project Puffin (more about this on Friday’s post!).

Among gulls that breed on the island Don Borror discovered a little songbird, a male Savannah Sparrow, that had established a territory and was singing his heart out to attract a female.

Savannah Sparrow

Enjoy the day with listening to the song of the Savannah Sparrow with the soundscape of coastal Maine.

About the author: Angelika Nelson is curator of the Borror Laboratory of Bioacoustics and instructor for Hog island Audubon camps.

Sucker Bridgework

July 1 2016June 28, 2016

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.

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 Sucker, Minytrema Melanops. Photo by Brian Zimmerman.

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

Smallmouth Buffalo, Ictiobus bubalus.

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

Shorthead Redhorse, Moxostoma macrolepidotum. Photo by Ben Cantrell.

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

River Redhorse Moxostoma carinatum. Photo by Uland Thomas.

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.

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

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Month: July 2016