Family Unionidae

Status:

Strophitus undulatus remains a common to abundant species in most of the metro area and throughout its range. However, in New Jersey it is designated a species of special concern. It occurs from Nova Scotia to Georgia on the Atlantic slope, and west to Saskatchewan and Texas, thriving in small, slow-moving water as well as larger rivers and lakes. S. undulatus is the only species of Strophitus occurring in the Atlantic region.

Species Summary

Strophitus undulatus (Say, 1817)
creeper

Features:

size: 100mm
beak: typically sharply defined, with coarse concentric sculpture slightly depressed
color patterns: fine green color rays may be apparent on posterior slope; periostracum yellowish or greenish, dark brown; nacre bicolored, white to bluish
shape: sub-ovate to sub-elliptical with posterior end blunt
shell features: shape variable; if beak sculpture is unclear, identification may be difficult
teeth: hinge teeth absent; pseudocardinals may be represented by a slight thickening of the nacre in each valve

Status:

abundance: common to abundant
status: US, NY, CT: not legally protected; NJ: special concern
conservation challenges: all freshwater mussels should be carefully monitored, and known locations surveyed on a regular basis to detect possible habitat degradation or  population declines; additional populations of Strophitus and other mussels should be actively sought

Distribution:

N.A. distribution: Nova Scotia (Canada) west to Saskatchewan, south to Pennsylvania and the Atlantic slope to Georgia; and from Ontario southwest through the Ohio and Mississippi River interior basin drainages to Texas
present metro distribution: NY: all watersheds; NJ: lower Hudson River watershed, upper Delaware River watershed; CT: Housatonic River watershed
other regional localities: NY: Lake Ontario watershed, upper Hudson River watershed; NJ: upper Hudson River watershed; CT: Connecticut, Housatonic and Thames River watersheds
historical localities: CT: lower Connecticut River watershed, South central coast watershed

Life History:

habitat: slow water of all sizes, and lakes; substrate: silt, sand, gravel and mixes Habitat Photo
hosts: Ambloplites rupestris (Rafinesque, 1817) rock bass; Ameiurus melas (Rafinesque, 1820) black bullhead; Ameiurus natalis (Lesueur, 1819) yellow bullhead; Campostoma anomalum (Rafinesque, 1820) stoneroller; Cottus cognatus (Richardson, 1836) slimy sculpin; Cubea inconstans (Kirtland, 1841) brook stickleback; Etheostoma caeruleum (Storer, 1845) rainbow darter; Etheostoma exile (Girard, 1859) Iowa darter; Etheostoma flabellare (Rafinesque, 1819) fantail darter; Etheostoma nigrum (Rafinesque, 1820) Johnny darter; Etheostoma olmstedi (Storer, 1842) tessellated darter; Fundulus zebrinus (Jordan and Gilbert, 1883) plains killifish; Ictaluns punctatus (Rafinesque, 1818) channel catfish; Lepomis cyanellus (Rafinesque, 1819) green sunfish; Lepomis gibbosus (Linnaeus, 1758) pumpkinseed; Lepomis macrochirus (Rafinesque, 1819) bluegill; Lota lota (Linnaeus, 1758) burbat; Luxilis cornutus (Mitchill, 1817) common shiner; Micropterus dolomica (Lacepede, 1802) smallmouth bass; Micropterus salmoides (Lacepede, 1802) largemouth bass; Nocomis micropogon (Cope, 1865) river chub; Notophthalmus vidridescens (Rafinesque, 1820) red-spotted newt; Notropis hudsonius (Clinton, 1824) spottail shiner; Notropis lundibundis (Girard, 1856) sand shiner; Oncorhynchus mykiss (Waldbaum, 1792) rainbow trout; Perca flavescens (Mitchill, 1814) yellow perch; Percina caprodes (Rafinesque, 1818) log perch; Percina maculata (Girard, 1859) blackside darter; Percina phoxocephala (Nelson, 1876) slenderhead darter; Pimephales notatus (Rafinesque, 1820) bluntnose minnow; Pimephales promelas (Rafinesque, 1820) fathead minnow; Pomoxis annularis (Rafinesque, 1818) white crappie; Pomoxis nigromaculatus (Lesueur, 1829) black crappie; Rhinichthys atratulus (Hermann, 1804) blacknose dace; Rhinichthys cartaractae (Valenciennes, 1842) longnose dace; Salvelinus fontinalis (Mitchill, 1814) brook charr; Semotilus atromaculatus (Mitchill, 1818) cheek chub; Stizostedion vitreum (Mitchill, 1818) walleye; Umbra limi (Kirtland, 1840) central mudminnow; also, no host required

Plates

S. undulatus

left valve	right valve
dorsal view	profile view
interior profile; bicolored nacre	teeth appear absent
beak sculpture coarse, concentric	pseudocardinals appear vestigial