Cyclotella cryptica can exhibit different morphologies depending on salinity. It can appear similar to C. meneghiniana, which generally has thicker walls than the typical form of C. cryptica, and a region of costae and intercostae that is delimited from the central region (Reimann et al. 1963; Schultz 1971). The diameter of C. cryptica can range from 5–25 µm depending on environmental conditions. In Lake Michigan, diameter ranges from 8–16 µm (Neümuller et al. 2002, Reimann et al. 1963, Stoermer and Yang 1969).

In marine and brackish environments, C. cryptica requires NO₃ as its source of nitrogen. It also requires Ni ions in order to grow autotrophically. It is capable of heterotrophic growth in the dark on glucose. This suggests it can survive for extended periods of time in bottom water or mud enriched in glucose. When environmental conditions higher in the water column improve, it probably resumes photoautotrophic growth. It is known to grow mesotrophically as well (Oliveira and Antia 1984, Reimann et al. 1963, Saros and Fritz 2000, White 1974).

Cyclotella cryptica produces an exudate that has the ability to suppress growth responses of other species such as Skeletonema costatum in environments enriched by vitamin B-12 (Messina and Baker 1982).

Cyclotella cryptica can generate auxospores from vegetative cells. It can also produce posteriorly flagellated male gamete stages (Hust et al. 1999, Schultz 1971).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Beneficial

There is little or no evidence to support that Cyclotella cryptica has significant environmental impacts in the Great Lakes.

Potential:
Cyclotella cryptica is a euryhaline species and within the Great Lakes is found primarily in nearshore areas, bays, and river mouths that have an elevated salinity (approximately 100-160 Cl^- mg/mL) due to salt pollution (Liu and Hellebust 1976, Makarewicz 1987). It does not itself affect water quality.

Cyclotella cryptica can grow heterotrophically for up to one year and could potentially outcompete native species in low or no light conditions, although this has not been recorded in the Great Lakes (White 1974).

There is little or no evidence to support that Cyclotella cryptica has significant socio-economic impacts in the Great Lakes.

There is little or no evidence to support that Cyclotella cryptica has significant beneficial effects in the Great Lakes.
Potential:
Cyclotella cryptica is a species that is important to the growing algal biofuels industry. Roessler (1988) found that C. cryptica grown in silica-deficient conditions had significantly higher levels of lipid production. Researchers are currently attempting to genetically engineer other species of algae that contains the acetyl-CoA carboxylase enzyme found in C. cryptica in order to increase lipid content (Day et al. 2012).

Regulations (pertaining to the Great Lakes region)
There are no known regulations for this species

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological
There are no known biological control methods for this species.

Physical
There are no known physical control methods for this species.

Chemical
There are no known chemical control methods for this species.

Other
Cyclotella cryptica is a euryhaline species (Liu and Hellebust 1976). As a result, reduction in run-off from winter road salt could decrease the chloride levels in the rivermouth areas and reduce the viable habitat for C. cryptica.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.