Introduction to Texas Freshwater Mussels and Taxonomic Updates
Gary Pandolfi Matt Johnson Malacologist Texas Freshwater Mussel Austin TX ESFO Conservation and Recovery Coordinator [email protected] Austin TX ESFO [email protected] Introduction: Gary Pandolfi
B.S. and M.S. in Biology/Ecology from Appalachian State University, NC Started with the Service in 2016 Currently, the Service species lead biologist for 8 mussels currently under review for potential ESA listing in Central and West Texas. Conducted mussel surveys across the southeast US 12 different states over the last decade. Performed surveys on about two dozen federally endangered species Main job duties include development of Species Status Assessments, scientific research project review and development, endangered species permitting through Sec 10(a)1(A), and occasional section 7 consultations Species lead biologist for 6 federally listed fishes in West Texas What are freshwater mussels?
Bivalve (two shells) invertebrates that filter feed or pedal (foot) feed Ancient family Unionidae that evolved from former marine mollusks, although all Unionids are freshwater Fossil records show North American appearance in the Devonian period (416-365 mya)
Photo - D. Strayer Photo – G. Pandolfi FWS Mussel Life Cycle
Unique life history, including parasitic juvenile life stage Fish host generalist or specialist depending on mussel species Host fish movements effect mussel recruitment and distribution
C. Barnhart
G. Pandolfi - FWS Why are mussels important?
Basal node of the food chain Food Resource (not only for humans) Mussels provide an ecological service, which saves us $$ Ecological Indicator
No Mussels Mussels Mussel Diversity Freshwater mussels are known to occur in every continent except Antarctica North America contains some of the highest species diversity in the world – 302 recognized species. More than 50 species occur in Texas
Photo(s): Mike Perkins and G. Pandolfi
Figure: Haag, 2012 Figure: mussel-project Freshwater Mussels Imperilment
Nearly 300 recognized species in North America alone Southeast USA is the global diversity hotspot for aquatic species Over 72% of the nearly 300 mussel species are considered to be some level of imperiled. Habitat Requirements
Substrate Suitable substrate requirements vary by species Cobble, gravel, sand, silt – Stability! Water Flow/Quantity Flow Regime Flow Refugia – area of stream bed that is not mobilized during high flooding events Water Quality – Pollution, ammonia, turbidity, conductivity, etc. Water Temperature – behavior, feeding rate, dissolved oxygen consumption and reproduction are all tied to temperature Mussel Habitats Mussel Habitats Mussel Habitats Mussel Threats
Habitat Alteration Sedimentation Pollution
Photos: M Perkins
Propagation Efforts in TX
Methods, equipment, and approach will vary wildly by species Most Texas species haven't been propagated before so it’s a learning process Inks Dam NFH showing good success with Texas fatmucket in 2019/2020 Questions? Introduction: Matt Johnson
B.S. and M.S. Virginia Tech Texas A&M University Natural Resources Institute Consulting stops in Virginia, Tennessee, and Texas
Completed several hundred mussel surveys and habitat assessments in 14 States and the Seneca Nation of Indians in southwest New York. Surveys completed in streams ranging from 4-ft wide creeks to large rivers like the Kanawha, Arkansas, and Ohio Rivers. Completed state and federal endangered species coordination for many mussel projects, including the preparation of survey reports, monitoring plans, Biological Assessments, etc. Propagated juveniles of common and federal/state-listed mussel species for augmentation and reintroduction projects in Virginia and Tennessee. Completed wetland and stream delineations, 404/401 wetland permitting, stream and wetland mitigation bank monitoring, rare plant surveys, herpetological surveys, and bald eagle and other avian surveys. Texas Freshwater Mussel Taxonomic Updates
Texas is home to three faunal groups and several endemic mussel species Rio Grande – Mexican species influence Central Texas – Texas endemics East Texas – Texas endemics/Mississippi Drainage influence “Texas is home to 52 species of freshwater mussels” Systematics started to be studies ~2015 Many Texas endemics are actually basin-level endemics Texas Hornshell Taxonomic Work
In 2016, Texas hornshell was proposed as endangered by the USFWS. The final rule was issued in March 2018.
Texas hornshell
Photo Credit: Mussels of Texas Questions of the species range came up during the proposal process
In 2017 and 2018, surveys were completed, and genetics samples collected from the Rio Grande to northern Veracruz in Mexico.
Genetic analysis confirmed that the species is endemic to the Rio Grande basin in Texas, New Mexico, and Mexico and other species in Mexico are other Popenaias sp. Photo Credit: M. Johnson, USFWS Golden Orb and Smooth Pimpleback
Johnson et al 2018 – determined these species are taxonomically invalid. The species were added to the “Pimpleback” (Cyclonaias pustulosa) group, which is a common and widespread species. Due to this taxonomic update, both are no longer considered valid species. These species were removed from review in 2019.
Pimpleback
Photo Credits: Mussels of Texas Guadalupe Basin Taxonomic Updates
In 2018/2019 the Texas fatmucket (Lampsilis bracteata) and Texas pimpleback (Cyclonaias petrina) were split, due to new taxonomic information. The Guadalupe fatmucket (Lampsilis bergmanni) and Guadalupe orb (Cyclonaias necki) were the newly described Guadalupe Basin endemics (Burlakova et al 2018, Johnson et al 2018). In March 2020, these two new mussels were added to the Texas Parks and Wildlife Department list of state False spike (Fusconaia mitchelli) threatened species Both species are currently recognized by the scientific community and Service
In September 2020, false spike was split, due to new taxonomic information. (Smith et al. 2020) The Guadalupe Basin populations of the false spike remained false spike. Guadalupe Basin Taxonomic Updates
Guadalupe orb (Cyclonaias necki)
Guadalupe fatmucket (Lampsilis bergmanni)
Texas pimpleback (Cyclonaias petrina)
Texas fatmucket (Lampsilis bracteata) Photo Credits: Mussels of Texas Colorado Basin Taxonomic Updates
In 2018/2019 the Texas fatmucket (Lampsilis bracteata) and Texas pimpleback (Cyclonaias petrina) were split, due to new taxonomic information.
In September 2020, false spike was split, due to new taxonomic information. (Smith et al. 2020)
The Colorado Basin populations of the false spike are now considered a new species, Balcones spike (Fusconaia iheringi)
Balcones spike hasn’t been recognized by the Service yet and both the Colorado and Guadalupe populations are currently still considered to be false spike (Fusconaia mitchelli)
Photo Credits: Mussels of Texas Brazos Basin Taxonomic Updates
In 2019, new genetic information determined that there are 3 species in the Potamilus ohiensis complex in Texas (Smith et al. 2019). Pink papershell (Potamilus ohiensis) – Common and widespread Texas heelsplitter (Potamilus amphichaenus) – Restricted to TX and LA, under review for listing under the ESA Brazos heelsplitter (Potamilus streckersoni) – Newly described Brazos River Basin endemic
In March 2020, the Brazos heelsplitter was added to the Texas Parks and Wildlife Department list of state threatened species
The Colorado Basin populations of the false spike are now considered a new species, Balcones spike (Fusconaia iheringi)
Balcones spike hasn’t been recognized by the Service yet and both are the Colorado and Guadalupe populations are currently still considered to be false spike (Fusconaia mitchelli) Brazos Basin Taxonomic Updates
Texas heelsplitter (Potamilus amphichaenus) Pink papershell (Potamilus ohiensis)
Brazos heelsplitter (Potamilus streckersoni)
Photo Credits: Mussels of Texas Trinity Basin Taxonomic Updates
In 2018, new genetic information determined that there are 4 species in the genus Fusconaia in Texas (Pieri et al. 2018). Texas pigtoe (Fusconaia askewi) – Found in the Sabine and Neches- Angelina drainages, State-threatened Wabash pigtoe (Fusconaia flava) – Mississippi basin embayment, Trinity, and San Jacinto drainages, common and widespread False spike / Balcones spike (Fusconaia mitchelli/Fusconaia iheringi) Trinity pigtoe (Fusconaia chunii) – Newly described species in the Trinity basin Still some debate on the validity of the Trinity pigtoe in the scientific community In March 2020, the Trinity pigtoe was added to the Texas Parks and Wildlife Department list of state threatened species Trinity Basin Taxonomic Updates
Trinity pigtoe (Fusconaia chunii) Trinity pigtoe (Fusconaia askewi)
False spike (Fusconaia mitchelli) Wabash pigtoe (Fusconaia flava)
Photo Credits: Mussels of Texas Mussels of Texas mussels.nri.tamu.edu Mussels of Texas mussels.nri.tamu.edu Mussels of Texas mussels.nri.tamu.edu Questions?
Gary Pandolfi Malacologist Austin TX ESFO [email protected]
Matt Johnson Texas Freshwater Mussel Conservation and Recovery Coordinator Austin TX ESFO [email protected]