Thursday, January 10, 2019

From Hagfishes to Halibuts, Thanks for All the Fishes. by Don Orth

More than one-half of the world’s living vertebrates are fishes.  With more than 69,000 vertebrate species, one must ask how we know that these facts are true (IUCN 2018).  Scientists around the world are continually adding to our knowledge and the names and numbers keep changing. It’s hard to check facts in news reports on the fishes. When I took Ichthyology as a student I learned that there were 18,818 species of fishes in the world. That's no longer true. The most up-to-date inventory indicates that there are 35,025 valid species of fishes in the world and 4,109 new species were added in the last ten years (Fricke et al. 2018).  That averages 411 species per year or more than 1 species per day!

In 1976, Joseph S. Nelson  published the first edition of Fishes of the World.  It was the definitive source of information on fish classification and a must-have reference for serious Ichthyologists.  New editions were published in 1984, 1994, 2006, and 2016.   The Catalog of Fishes maintained by the California Academy of Science  provides online information for all fish species and other web-based databases, such as FishBasmake ichthyological fact checking easier (Froese and Pauly 2018).  

Number of valid fish species, families, and orders recognized in Fishes of the World by publication year.  Data for 2019 from Catalog of Fishes.


The most recent edition of Fishes of the World captures the explosion of published research on fishes and the emergency of 3D scanning, Next-Gen sequencing, molecular systematics, and large collaborative projects, such as the NSF All Catfish Species Inventory and Cypriniform, Euteleost, and Chondrichthyan Tree of Life projects.  From the most recent Catalog of Fishes, the three largest fish families are the Gobiidae, Cichlidae, and Cyprinidae.  Some familiar families of fish are monotypic, which means there is only one species.   Monotypic families include the familiar Whale Shark Rhincodontidae, Megamouth shark Megachasmidae, Bowfin Amiidae, Milkfish Chanidae, Salamanderfish Lepidogalaxiidae, Pirate Perch Aphredoderidae, Swordfish Xiphiidae, and Louvar Luvaridae. 

Top thirteen fish families (based on number of valid species) and number of species added in last ten years (Fricke et al. 2019)
Family Name
Common Name
New Species
Minnows and Carps
Suckermouth Armored Catfishes
Stone Loaches
True Minnows
Sea Basses and Groupers

The changes in numbers are due to discovery, lumping, splitting, and changes in classification.   The snailfishes Liparidae are deepwater fishes and pioneering video technology is responsible for discovery of many new snailfish species  In other cases, reexamination of collected specimens may result in splitting species into several new species (e.g., Collins et al. 2017).  In other cases, the rarity of the species can explain how it was overlooked until recently.   In other cases, changes in numbers is due to a wholesale revision of the systematics (e.g., Cypriniformes Tan and Armbruster 2018).
Pseudolithoxus nicoi is an armored catfish endemic to Columbia and Venezula was recently split into two species (Collins et al. 2017.  Photo by
Among the new species discovered in 2018, are the Sailfin Fairy Wrasse and the Sunset Perchlet found during a survey of the deep reefs of Easter Island (Rowlett 2019).   
Sailfin Fairy Wrasse, AKA Blue Thorat Fairy Wrasse (Cirrhlabrus cyanogularis) Credit: Y.K. Tea / Tea et al. 2018
Sunset Perchlet Plectranthias ahiahiata, holotype, 39.95mm. Credit: Luiz Rocha / Shepherd et al. 2018
It’s not common for scientists to discover a new family of fishes.   However, in 2018 a new family was discovered from the Amazon (de Pinna et al. 2017).   This new species Tarumania was collected in isolated pools of tributaries of the Rio Negro where it is capable of burrowing in decomposing leaf litter and gulping air.  Why a new family?   There is no family in which to place this strange new fish with a curiously shaped swimbladder, eel shaped body, and scales on the head that face forward. 
Tarumania walkerae holotype. Credit: De Pinna et al. 2017

Novice and experienced Ichthyologists often struggle with the names of fishes because the precise meaning of many names is poorly known.  There is no definitive reference for the latinized names given.  The local endemic Bigmouth Chub Nocomis platyrhynchus was named from the Greek platurrhunkhos meaning “broad snouted” In the species description Lachner and Jenkins (1971, p. 39) wrote "the specific names, platyrhynchus, and the vernacular name, bigmouth chub, is in reference to the large gape width." The genus name Nocomis was given by Charles Frédéric Girard apparently because he liked the sound of the native American word, Nokomis which means grandmother.  Fish names are researched by The ETYFish project  and archived in the  Fish Name Etymology Database developed by Christopher Scharpf and Kenneth J. Lazara. In the North America, a group of fish taxonomist meet periodically and published the Common and Scientific Namesof Fishes form United States, Canada, and Mexico.   In the 2013 edition, they report on 3,875 species and 260 families.

Knowledge of fish numbers is essential for estimating extinction rates and providing a baseline for protection of rare and common fishes.  Fish taxonomy is an often overlooked specialty and the lack of support for taxonomy is a threat to biodiversity conservation.  For example, almost half of the nineteen species of popular black basses Micropterus spp., have been identified in the last twenty years (Taylor et al. 2019).  New fish species discoveries are a testament to the perseverance of dedicated taxonomists.  But the rate is slow and many cryptic fish species remain hidden or lumped with similar forms due to lack of analysis 


Collins, R.A.,  et al. 2017.  Biogeography and species delimitation of the rheophilic suckermouth catfish genus Pseudolithoxus (Siluriformes: Loricariidae), with the description of a new species from the Brazilian Amazon.  Systematics and Biodiversity 16:538-550. 

De Pinna, M.,  J. Zuanon, L. R. Py-Daniel, and P. Petry. 2018. A new family of neotropical freshwater fishes from deep fossorial Amazonian habitat, with a reappraisal of morphological characiform phylogeny (Teleostei: Ostariophysi). Zoological Journal of the Linnean Society, zlx028,

Fricke, R., W.N. Eschmeyer, and R. van der Laan, editors.  2019. CATALOG OF FISHES:
GENERA, SPECIES, REFERENCES. ( Electronic version accessed 9 January 2019.

Froese, R. and D. Pauly. Editors. 2018. FishBase. World Wide Web electronic publication., version (06/2018).

IUCN Red List of Threatened Species, Table 1: Numbers of threatened species by major groups of organisms (1996–2018) Source

Lachner, E.A., and R.E. Jenkins,. 1971.  Systematics, distribution, and evolution of the chub genus Nocomis Girard (Pisces, Cyprindae) of eastern United States, with descriptions of new species.  Smithsonian Contributions to Zoology, Number 85.   97 pp.  

Rowlett, J. 2019.  Top ten new fish species from 2018.  World Wide Web.   accessed 9 January.

Tan, M. and J. W. Armbruster.  2018. Phylogenetic classification of extant genera of fishes of the order Cypriniformes (Teleostei: Ostariophysi). Zootaxa 4476 (no. 1): 6-39.

Taylor, A.T., J.M. Long, M.D. Tringali, and B.L. Barthel. 2019.  Conservation of black bass diversity: An emerging management paradigmFisheries  43

Saturday, December 29, 2018

Fluvial Fishes Lab Year in Review

New Year’s Day… now is the accepted time to make your regular annual good resolutions. Next week you can begin paving hell with them as usual.”  Mark Twain
Many of my good intentions were realized in 2018.  The year ended with the delivery of the completed layout for the Field Guide to Freshwater Fishes of Virginia to Johns Hopkins University Press.  Six coauthors (Paul E. Bugas, Jr., Corbin D. Hilling, Val Kells, Michael J. Pinder, Derek A. Wheaton, and Donald J. Orth) developed this up-to-date field guide to all the freshwater fishes of Virginia.  The guide contains in introduction to the study of Virginia's freshwater fishes, a key to the families, 175 color illustrations, 29 color photos, illustrations of diagnostic characteristics, range maps, descriptions of the 225 species of freshwater fishes, glossary, and index.  If you need to know what fish is also called the "Gaspergou," you can find the answer in this guide.  Many fish facts are included in the species accounts and species newly discovered are included.   Other publications are listed below along with several favorite blog posts and photos from Ichthyology class.

Poster presentation on Field Guide to Freshwater Fishes of Virginia.  Click for link.
Publications for 2018

Bugas, P.E., Jr., C.D. Hilling, V. Kells, M.J. Pinder, D.A. Wheaton, and D.J. Orth. In press. Field Guide to the Freshwater Fishes of Virginia. Johns Hopkins University Press, Baltimore, Maryland.  expected Sept. 2019.

Carey, C.S., D.J. Orth, and V. Emrick. 2018. Biological Surveys for Fries Hydroelectric Project in the upper New River, Grayson County, Virginia. Final Report to TRC Solutions, Reston, Virginia.  Conservation Management Institute, Department of Fish and Wildlife Conservation, College of Natural Resources and Environment, Virginia Polytechnic Institute and State University, Blacksburg, VTCMI-04-2018.  65 pp. 

Fries Dam, Fries, Virginia, at low flow.  Photo by D.J. Orth.
Dickinson, B.D., S.L. McMullin, D.J. Orth, and J.R. Copeland. 2018. Trotline catch rates vary by hook and bait type in the New River, Virginia. Journal of the Southeastern Association of Fish and Wildlife Agencies.  5:46-52.
Hilling, C.D., S.L.Wolfe, J.R. Copeland, D.J. Orth, E. M. Hallerman. 2018.   Occurrence of two non-indigenous catostomid fishes in the New River, Virginia. Northeastern Naturalist 25(2):215-221.  DOI: 10.1656/045.025.0204     Link to DNA Barcoding video.

Hilling, C.D., A.J. Bunch, R.S. Greenlee, D.J. Orth and Y. Jiao.  2018. Natural mortality and size structure of introduced Blue Catfish in Virginia tidal rivers. Journal of the Southeastern Association of Fish and Wildlife Agencies 5:30-38.

Moore, M.J., and D.J. Orth. 2018. Stories worth sharing.  Fisheries  43(12):575-576.   Link to Michael J. Moore video story My Dog Ate My Lab Notebook. 

Moore, M.J., D.J. Orth, and E.M. Hallerman. 2018. Multi-metric conservation assessment for the imperiled Clinch Dace. Southeastern Fishes Council Proceedings 58:31-56.

Orth, D.J.  2018.  Social media may empower fisheries students via learning networks.  Fisheries  43(3):130-138.

Orth, D. 2018. Learning lessons about Lampreys.  American Currents 43(3):11-16.

Orth, D.J. In press.  Socrates opens a Pandora’s box of Northern Snakehead issues. Pages 000-000 in D. Chapman and J. Odenkirk, editors.  First International Snakehead Symposium, American Fisheries Society, Bethesda, Maryland.

Schmitt, J.D., B.K. Peoples, L. Castello, and D.J. Orth. 2018. Feeding ecology of generalist consumers: a case study of invasive blue catfish Ictalurus furcatus in Chesapeake Bay, Virginia, USA. Environmental Biology of Fishes DOI: 10.1007/s10641-018-0783-6

Stang, S.A., C.D. Hilling, and D.J. Orth. In press.  Lessons learned from 35 years of students organizing the Mudbass Classic. Fisheries  44

Outreach for 2018 

Joseph Schmitt defended his dissertation and moved on to a position as Fisheries Research Biologist with the USGS investigating Lake Erie fisheries.  Corbin Hilling was awarded a 2-year Virginia Sea Grant Fellowship to further his studies of the nonnative Blue Catfish in tidal rivers.    See news release.
Corbin Hilling, doctoral student, received Virginia Sea Grant Fellowship in 2018.
There are new writings and activities on the outreach front. Stories about the non-native catfish appear regularly in a blog, managed by PhD student, Corbin Hilling, and Joseph Schmitt, PhD.  The most recent was an interview with Captain John a recreational fishing guide for Blue Catfish on the James River.  See ChesapeakeCatfish.   Corbin Hilling recently taught a group of young 4-H students about fishes (see below) and Don Orth taught Master Naturalists in the Southwest Piedmont chapter about the fishes of Virginia.   With Dan Goetz and Aaron Bunch of the Virginia Department of Game and Inland Fisheries, we organized and presented a Continuing Education session on Field Sampling Design and Statistical Power. 
My lab coat was decorated with Gyotaku by a group of young students. Photo by D.J. Orth.
Illustration of the Atlantic cutlassfish, or ribbonfish, Trichiurus lepturus (above) and student's model (below).  Photo by Corbin Hilling. 
Don Orth after presenting paper at Virginia Chapter AFS meeting in Fredericksburg, Virginia. Photo by Valerie Orth
The #25daysofFishmas hashtag on Twitter celebrated Great Lakes Fishes, thanks to Katie O'Reilly, who organized daily tweets since 2016. The Virginia Tech Ichthyology Facebook group joined in for 2018.  You may follow the fishes highlighted for each of the 25 days of Fishmas, starting with the Mahi Mahi.   

Photos from Ichthyology 2018 

Species of Petromyzontidae in Virginia.  Photo and illustrations by Hanna Infanti.
Students dissect a Walleye collected from New River. Photo by D.J. Orth.
Learning to distinguish the Moxostoma is given more than lip service.  Photo by Taylor Comer

Pharyngeal arch removed from a minnow. Photo by Jared Rodenas.
Fish memes help us remember scientific names. Photo by D.J. Orth.
Cheers to 2019!  If interested, follow our blog,  join Virginia Tech Ichthyology on Facebook and/or follow Fluvial Fishes Lab on Twitter @donaldorth