What's New In the World of Freshwater Fishes of Virginia? by Don Orth

The Field Guide to the Freshwater Fishes of Virginia will be released by September 24^th. I promise that even those familiar with our local fish fauna will learn something new.  I’ve received many questions about the forthcoming Field Guide and answer a few of them here. 

How many freshwater fish species are there in Virginia?  There are more species (226) and more families (28) of freshwater fishes than appeared in Jenkins and Burkhead (1994) treatise.  How’d that happen?  It’s a combination of discoveries of cryptic diversity, introductions, and elevation of subspecies to species status. 

Families                                  Species in Virginia

Lampreys - Petromyzontidae              5

Sturgeons - Acipenseridae                  2

Paddlefish – Polyodontidae                1

Gars – Lepisosteidae                          1

Bowfins – Amiidae                            1

Eels – Anguillidae                              1

Herrings – Clupeidae                          6

Carps and allies - Cyprinidae             1

Carps - Xenocyprididae – Carps        1

Minnows – Leuciscidae                      71

Suckers – Catostomidae                     19

Catfishes – Ictaluridae                        15

Trouts – Salmonidae                           3

Pikes – Esocidae¹                                4

Mudminnows – Umbridae¹                1   

Pirate Perch – Aphredoderidae           1

Cavefishes – Amblyopsidae               1

Silversides – Atherinopsidae              1

Killifishes – Fundulidae                     5

Livebearers – Poeciliidae                   1

Sticklebacks – Gasterosteidae            1

Sculpins – Cottidae                             10

Temperate Basses – Moronidae          3

Sunfishes – Centrarchidae                  20

Perches – Percidae                              48

Drums – Sciaenidae                            1

Snakeheads – Channidae                    1

¹Note: some call for merger of Esocidae and Umbridae

Outline sketch of members of the Leuciscidae, formerly Leuciscinae, Cyprinidae

What the most species rich group?  The order Cypriniformes is the most diverse order of freshwater fishes in the world, numbering over 4,602 currently recognized species (Fricke et al. 2019).  This is more than 200 new Cypriniformes species since we first began working on the Field Guide. 

What major taxonomic revision has occurred recently? The former subfamily Leuciscinae was elevated to family level (Tan and Armbruster 2018). Leuciscidae has 680 species and this now includes what we used to consider the native North American Cyprinidae as well as some European and Asian minnows.  In Virginia, we find 71 species in the newly defined Leuciscidae, making this the most species-rich family in freshwaters of Virginia. Xenocyprididae encompases the introduced fish we know as Ctenopharyngodon idella – Grass Carp. Cyprinidae includes 1,722 valid species, such as the Common Carp, as well as other carps, barbs and barbels, and tor.    

What about the darters? There are 238 valid species of Percidae in the world and most of these are darters.   Virginia has 48 species of Percidae, 45 are darters in Ammocrypta, Percina, and Etheostoma. 

How come Virginia has such high number of freshwater fishes?

Virginia has a humid, temperate climate with about 43 inches of rainfall annually. In this relatively wet environment, differences in geology and topography provide diverse aquatic habitats and thermal regimes enabling a wide diversity of fish species to evolve and thrive. Historical factors, such as the lack of Pleistocene glaciers, interconnections between river systems, and species dispersal patterns, all contribute to Virginia’s rich fish fauna.  Virginia has five landforms, each with distinct geologic histories and freshwater habitats.  These are depicted on the map below -- Appalachian Plateau, Ridge and Valley, Blue Ridge, Piedmont, and Coastal Plain. Virginia’s highest peak is Mount Rogers at 5,729 feet above sea level.

Map of Virginia color coded by elevation (blue is low, red is high) and physiographic provinces. Map produced by coauthor Corbin Hilling.   If you don't know physiographic provinces, get the Field Guide.

Which drainage has the most nonnative fishes?   The New drainage has only 40 native fishes and an additional 46 species are introduced.

What species are extirpated from Virginia?

Cyprinella labrosa – Thicklip Chub

Moxostoma lacerum – Harelip Sucker

Percopsis omiscomaycus – Trout-perch Percopsidae

Percina bimaculata – Chesapeake Logperch

What is the rarest fish species of Virginia?

Erimystax cahni – Slender Chub

What is species is the newest introduction to Virginia? 

Channa argus – Northern Snakehead

What family has the most cryptic diversity?  Cottidae

What species still need of formal species descriptions?

Chrosomus sp. cf. saylori – Clinch Dace

Notropis sp. cf. spectrunculus – Sawfin Shiner

Moxostoma sp. cf. lachneri – Brassy Jumprock

Cottus n. sp.  Bluestone Sculpin

Cottus n. sp. Clinch Sculpin

Cottus n. sp. Holston Sculpin

Probably other Cottus

 

What colloquial fish name is unique to Virginia?   Shenandoah Tarpon is used by anglers who have caught the Fallfish Semotilus corporalis via flyfishing.

 

What species are Endangered? 

            Acipenser oxyrinchus Atlantic Sturgeon

            Acipenser brevirostrum Shortnose Sturgeon

            Etheostoma osburni Candy Darter

            Etheostoma percnurum Duskytail Darter

            Percina rex Roanoke Logperch

What species are Threatened?

Chrosomus cumberlandensis Blackside Dace

Erimystax cahni Slender Chub

Erimonax monachus syn: Cyprinella monacha Spotfin Chub

Noturus flavipinnis Yellowfin Madtom

What’s the most colorful fish in Virginia?  That’s a toss up between the

            Chrosomus oreas Mountain Redbelly Dace and

            Etheostoma osburni Candy Darter

You’ll have judge for yourself. Each of these colorful species was illustrated by Val Kells. 

Michael J. Pinder, coauthor, and Yellowfin Madtom Recovery t-shirt at the release in the North Fork Holston River.  Photos by David Crigger, Bristol Herald Courier

What rare fish has high promise for recovery?  The Yellowfin Madtom has been cultured in captivity and can be introduced into streams of its historic range. 

What is the most cultured species in Virginia?   More than 1.5 million trout are produced in Virginia's 5 trout hatcheries each year.  Most of these are Rainbow Trout Oncorhynchus mykiss. 

Most underappreciated cool fish in Virginia?   Swampfish Chologaster cornuta

What species has the smallest range?

Etheostoma percnurum – Duskytail Darter occurs only in Copper Creek. 

Duskytail Darter Etheostoma percnurum.  Illustration by J. Sipiorski (Blanton et al. 2008)

What’s the best fish story? That would have to be the sturgeons (Acipenseridae).  These ancient bony fishes lived during the Cretaceous period during the age of dinosaurs (145.5 and 65.5 million years ago). Sturgeons are one of the largest and longest-lived anadromous fish in North America and two species occur in Virginia waters.  The Atlantic Sturgeon may reach a maximum size of 14 feet and 811 pounds based on a Canadian specimen.  The population has been depleted coast wide for a long time.  During the late 1800s, fishing for sturgeon eggs (to sell as caviar) attracted so many people, the trend was referred to as the “Black Gold Rush.” Atlantic Sturgeon were thought to be gone from Maryland waters of the Chesapeake Bay, but recent good news indicates they are still there. Also, Atlantic Sturgeon are reproducing in the James River.

Albert Spells, Virginia Fisheries coordinator for the Fish and Wildlife Service, didn’t believe Atlantic sturgeon were gone from the Chesapeake Bay watershed. Photo by USFWS

How many field guides do you plan to sell?  Based on US Census figures, there are 8.57 million people in Virginia, 78% are over 18, and 8% fish.  If all anglers in Virginia buy a Field Guide, we will sell 534,768 copies.  😉  Pre-order now and receive a 20% discount from the publisher.  

References

Blanton, R.E., and R.E. Jenkins. 2008. Three new darter species of the Etheostoma percnurum species complex (Percidae, subgenus Catonotus) from the Tennessee and Cumberland river drainages.  Zootaxa 1963:1-24.

Fricke, R., W.N. Eschmeyer, and R. van der Laan, editors.  2019.  CATALOG OF FISHES: GENERA, SPECIES, REFERENCES.  Accessed August 2, 2019 (http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp).

Jenkins, R.E., and N.M. Burkhead. 1994.  Freshwater Fishes of Virginia.  American Fisheries Society, Bethesda, Maryland.  1080 pp.

Tan, M., and J.W. Armbruster. 2018. Phylogenetic classification of extant genera of fishes of the order Cypriniformes (Teleostei: Ostariophysi).  Zootaxa 4476(1):6-39.

Hackelbacks and Old Spade Face, by Don Orth

Scaphirhynchus sturgeons arose in North America but remain among the least studied fishes.  Scaphirhynchus is pronounced Ska-fur-rink-us. Fossils resembling the ancestral Scaphirhynchus were dated from the late Cretaceous (Grande and Hilton 2006).  This fossil (pictured below) was discovered in modern day Montana and the sturgeon swam in rivers at the same time that Tyranosaurus rex, Hadrosaurs, and Ceretopsians roamed the Cretaceous landscapes 70 million years ago.  The sturgeon fishes (Acipenseridae) date back 200 million years and sturgeons exist in all continents of the northern hemisphere. The sturgeons are primarily cartilaginous and lack a backbone with separate vertebrae.  The closest relative of the Scaphirhynchus sturgeons are members of the genus Pseudoscaphirhynchus, which includes three critically endangered species from the Aral Sea basin.  The Scaphirhynchus sturgeons are ideally suited for life in large, fast flowing rivers that formed when the Rocky Mountains arose and the great inland sea receded. Recent molecular genetics methods confirmed the distinctiveness of three species: Shovelnose Sturgeon Scaphirhynchus platorynchus, Pallid Sturgeon Scaphirhynchus albus, and Alabama sturgeon Scaphirhynchus suttkusi (Ray et al. 2007).

Illustration of a specimen named Scaphirhynchus rafinesquii by Jacob Heckel 1836

Fossil sturgeon Priscosturion longipinnis from ~78 MYA. Image from The Field Museum photo archives image A93851c, Chicago, Illinois. photo by Eric Hilton source

The current status of the three Scaphirhynchus sturgeons is precarious due to harvest and dams. Too much harvest means too few breeders.  Too many dams impede the free-flowing river habitat needed for spawning and early development of young shovelnose sturgeons. Pallid Sturgeon is the largest of the three and critically endangered.  The Pallid Sturgeon recovery program  involves three regional teams that must coordinate and implement recovery actions for pallid sturgeon in Recovery Priority Management Areas encompassing the waters of the Missouri and lower Mississippi River basins of the United States.   Watch this video to get a better idea of recovery actions. 

 

Alabama Sturgeon was feared to be extinct as the last specimen handled by a biologist was in 2007.  Watch this video that describes the recent discovery of environmental DNA of the Alabama Sturgeon. Twenty-five major locks and dams on the rivers of the Mobile Basin fragment the habitat where the Alabama Sturgeon lives.  Shovelnose Sturgeon are listed as threatened because their current range is greatly reduced (Phelps et al. 2017).  

It’s mind boggling to consider the millions of years of survival of the ancestral Scaphirhynchus sturgeon through many major climate disruptions, mass extinction, multiple glacial advances and retreats, and river course changes.  The three species of shovelnose sturgeon are well adapted for life in the murky waters.  Shovelnose Sturgeon complete all aspects of their life cycle in the main channel of rivers. They are often caught by anglers who fish with worms in shifting sands.  Here the anglers call them “Sand Sturgeon” because of their behavior of holding position in sand and associated dune bedforms even at high flows. 

 

Illustrations of the Pallid Sturgeon (top), Shovenose Sturgeon (middle), and Alabama Sturgeon (bottom).  Sources:    Fishes of Illinois, Flickr,  and Patrick O’Neil  Fishes of Alabama.  Note: the long caudal filaments are typical of only young sturgeon (< 40mm). 

Tens of millions of years living in the large muddy rivers produced a fish with body form and adaptations like no other fish.  The shape of the head earned it the name “old spade face” and “flathead sturgeon” and the bony scutes on the mid-dorsal ridge gave it the name “hackleback.”  The mouth is ventrally located and protrusible and the snout has four long barbels in front of the mouth.

Ventral surface of the head of Shovelnose Sturgeon. Photo by Corey Raimond

Close up of the head of "Old Spade Face" or Shovelnose Sturgeon in Missouri River. Photo by Sam Stukel. 

Sturgeons throughout the world are at risk of overharvest due to the lucrative caviar market.   The Shovelnose Sturgeon is no exception and commercial harvesters in Arkansas, Kentucky, Illinois, Indiana, Iowa, Missouri, Tennessee, and Wisconsin target Shovelnose Sturgeon, many solely for the roe markets (Koch and Quist 2010).  The caviar is marketed as Hackelback caviar and sells for $24 per ounce.  Therefore, an individual gravid female can be worth thousands of dollars.   Harvest pressure to meet the caviar market demands will increase. Therefore, harvest restrictions, which vary among states, are needed to protect populations from overharvest (Koch and Quist 2010). 

Hackelback Sturgeon caviar  Source

The Scaphirhynchus sturgeons have morphological adaptations that are very unique.  The small, adhesive eggs develop quickly into yolk sac larvae which develop as they drift with river currents. Consequently, reservoirs and backwater habitats allow the larvae to sink to the bottom instead of staying in the drift.   The drift hypothesis maintains that the small sturgeon larvae must have sufficient river length in order to drift and develop for many days.  Consequently, Scaphirhynchus sturgeons need spawning grounds and sufficient river length for larval development and drift for populations to persist.  

Yolk sac larva of Shovelnose Sturgeon.  Illustration by Murrie V. Graser

  Juvenile shovelnose sturgeon. USFWS.

The head, bony scutes, barbels with dense arrays of taste buds, and a spiral valve intestine are additional morphological traits unique to the Scaphirhynchus sturgeons.  The bottom of the body is a flat plane,  protected with bony denticles, which allow the fish to swim right at the river bottom and be protected from abrasion.  The body surface is protected by rows of large bony scutes interspersed with smaller denticles.  The mid dorsal, lateral, and ventral ridges form distinct keels. The combination of a flat head, small gas bladder and long caudal filament serves to align the fish in the current but close to the bottom. The whiptail or caudal filament is often lost among older specimens.  They possess numerous electrosensory pit organs on the ventral surface of the rostrum, large nares,  and numerous taste buds on papillose barbels, lips, gill rakers and esophagus (Weisel 1979).   Electrosensory and chemosensory organs all of which serve to facilitate efficient feeding on benthic or drift-feeding invertivores, feeding largely on Trichoptera, Ephemeroptera, Chironomidae, and other small invertebrates (Phelps et al. 2017).   These benthic organisms are consumed via a highly protractile mouth, extending 2/3rds of the head depth.   Digestion is also facilitated by a spiral valve intestine, a highly coiled structure to increase nutrient absorption.  Spiral valve intestines are only present in sharks, skates, rays, and primitive bony fishes.

Scalation pattern from dorsal to ventral for Shovelnose Sturgeon (Weisel 1978)

Head of Shovelnose Sturgeon showing protrusible mouth and barbels (Weisel 1979).

Papillae on barbel of Shovelnose Sturgeon. (Weisel 1979)

Diagram of viscera of the Shovelnose Sturgeon (Weisel 1979).

Like many large riverine fishes, the Shovelnose Sturgeon relies on movement through a mosaic of different habitats as they grow and complete their life cycle (Phelps et al. 2017).   Quinton Phelps, Assistant Professor at West Virginia University, recorded one Shovelnose Sturgeon that moved over 1,000 miles in a single year and others that traveled more than 500 miles in one year.   Therefore, long, undammed and multiple rivers are essential to sustain our remaining Shovelnose Sturgeon populations. These rivers are working rivers that drain industrial and agricultural watersheds and serve as navigation channels for commercial barge traffic.  Habitat degradation, river connectivity, industrial contaminants (PCBs), and entrainment in tow barge prop wash remain contemporary concerns for viability of Shovelnose Sturgeon populations.  Old Spade Face just might live on for many more millions of years.

References

Grande, L., and E.J. Hilton. 2006.  An exquisitely preserved skeleton representing a primitive sturgeon from the Upper Cretaceous Judith River formation of Montana (Acipenseriformes: Acipenseridae: n. gen. and sp.). Memoirs Journal Paleontology 80:1–39.

Heckel, J. J.  1836. Scaphirhynchus, eine neue Fischgattung aus der Ordnung der Chondropterygier mit freien Kiemen. Annalen des Wiener Museums der Naturgeschichte v. 1: 69-78, Pl. 8. 

Koch, J.D., and M.C. Quist. 2010. Current status and trends in shovelnose sturgeon (Scaphirhynchus platorynchus) management and conservation.  Journal of Applied Ichthyology 26:491-498.

Phelps, Q., S.J. Tripp, M.J. Hamel, J. Koch, E.J. Heist, J.E. Garvey, K.M. Kappenman, and M.A.H. Webb.  2017.  Status of knowledge of the Shovelnose Sturgeon (Scaphirhynchus platorynchus, Rafinesque, 1820).  Journal of Applied Ichthyology 32(Suppl. 1):249-260.

Ray, J.M., C.B. Dillman, R.M. Wood, B.R. Kuhajda, and R.L. Mayden. 2007: Microsatellite variation among river sturgeons of the genus Scaphirhynchus (Actinopterygii: Acipenseridae): a preliminary assessment of hybridization. Journal of Applied Ichthyology 23:304– 312.

Weisel, G.F, 1978. The integument and caudal filament of the Shovelnose Sturgeon, Scaphirhynchus platorynchus.  The American Midland Naturalist 100:179-189.

Weisel, G.F. 1979. Histology and the feeding and digestive organs of the Shovelnose Sturgeon.  Copeia 1979:518-525.