Species Description: Crepidula cf. plana is similar to Crepidula plana but has direct development as opposed to a short planktonic stage. The 2 species are similar in appearance, but C. cf. plana is significantly smaller at only 5 - 8 mm in length. Shells are oval and flat in appearance, and white in color. Both C. plana and C. cf. plana can be found inside empty shells of whelks and moon snails. C. cf. plana is expected to be renamed.
Potentially Misidentified Species: Species is very similar to Crepidula plana, the eastern white slippersnail.
Regional Occurrence: The northernmost extent of the range of Crepidula plana and its close relatives, including C. cf. plana, is eastern Canada. C. plana ranges south to the Gulf of Mexico.
IRL Distribution: Crepidula cf. plana is found throughout the Indian River Lagoon.
Age, Size, Lifespan: Males of Crepidula cf. plana are characteristically smaller than females. Minimum, typical and maximum sizes for males are: 1, 5 and 8 mm respectively; for females, these sizes are: 5, 10 and 16 mm. Longevity for male C. cf. plana is typically 6 months but females can live for 2 years. However, the size and sex change of Crepidula cf. plana often depends on the social structure of a population as well as on environmental conditions.
Reproduction: Crepidula cf. plana is a protandric hermaphrodite which is reproductively active year round. It has as many as 6 reproductive periods per year, producing from 100 to 200 young. Reproductive seasonality peaks during the summer for this species.
Embryology: Eggs in Crepidula cf. plana are brooded. Typical larval development time is 21 days, but can range from 14 to 28 days.
Temperature: Crepidula cf. plana is considered eurythermic. Temperature ranges; records from a data logger in the Indian River Lagoon show that C. cf. plana tolerates a temperature range between 5 - 35°C.
Salinity: Crepidula cf. plana is oligohaline to euryhaline. Salinity ranges, recorded from a data logger in the Indian River Lagoon show that this species tolerates salinities between 15 - 38 ppt.
Other Physical Tolerances: C. cf. plana prefers well oxygenated conditions.
Trophic Mode: Juvenile and adult Crepidula cf. plana are suspension feeders.
Habitat: Crepidula cf. plana prefers epibenthic habitats in oyster reefs. Crepidula cf. plana is located intertidally to subtidally with low wave exposure, preferring slow flowing water conditions.
Collin R. 2000. Phylogeny of the Crepidula plana (Gastropoda: Calyptraeidae) cryptic species complex in North America. Canad J Zool 78: 1500-1514.
Lima GM, Pechenik JA. 1985. The influence of temperature on growth rate and length of larval life of the gastropod, Crepidula plana Say. J Exp Mar Biol Ecol 90: 55-71.
Mikkelsen PM, Mikkelsen PS, Karlen DJ. 1995. Molluscan biodiversity in the Indian River Lagoon, Florida. Bull Mar Sci 57: 94-127.
Pechenik JA, Hilbish TJ, Eyster LS, Marshall D. 1996. Relationship between larval and juvenile growth rates in two marine gastropods, Crepidula plana and C. fornicata. Mar Biol 125: 119-127.
Zimmerman KM, Pechenik JA. 1991. How do temperature and salinity affect relative rates of growth, morphological differentiation, and time to metamorphic competence in larvae of the marine gastropod Crepidula plana? Biol Bull 180: 372-386.