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Daphnia catawba
Phylum Arthropoda
Subphylum Crustacea
Class Branchiopoda
Order Cladocera
Family Daphniidae
Ecology and Behavior
  • Rostrum present
  • Cervical sinus absent
  • Postabdominal claw with middle pecten the largest, with two to five teeth at least three times as long as distal pecten
  • Optic vesicle not touching margin of head
  • Interspinule distance two to three times spinule length
Similar Species
    Daphnia catawba and D. schødleri are extremely similar and distinguished from one another, primarily on the distance between the spinules on the dorsal margin of the carapace.  D. catawba has relatively short spinules that are separated from one another by at least 1.5 spinule lengths, whereas D. schødleri has much longer spinules that nearly overlap.
Geographic Distribution
    D. catawba is widely reported in the northeastern region of North America.  It is found in lakes in Newfoundland, New Brunswick, Ontario, Connecticut (1) and New Hampshire (2).  D. catawba is also located in Wisconsin (3) and North Carolina (1).
Reproductive Habits
    The timing of D. catawba's cyclic parthenogenesis, i.e. periods of asexual reproduction followed by sexual reproduction, is strongly dependent on temperature (1)(2)(3). Such a predominantly northern species could be impacted by climate change. For example, periods of warm weather in the fall could cause D. catawba to revert to asexual reproduction, reducing the abundance of diapausing ephippia and thereby altering the distribution of this daphnid (3).
    Chaoborus (4) and planktivorous fish prey on D. catawba in the summer (2). Chaoborus-induced neckteeth may have only one spine.
    In the summer, D. catawba may compete with Holopedium gibberum for food, resulting in a decline of H. gibberum populations (2).
    D. catawba has a nocturnal diel vertical migration, migrating upward at dusk and downward at dawn (2).
Seasonal Variations
    In Lake Lacawac, a small glacial lake in northeastern Pennsylvania, the population of D. catawba increased rapidly in April associated with warming temperatures and high particulate organic matter.   D. catawba population was minimal in midsummer most likely due to predation by fish and competition for food (2).

(1) HERBERT, P. D. N., AND T. L FINSTON. 1997. A taxonomic reevaluation of North American Daphnia (Crustacea: Cladocera). III.  The D. catawba complex.  Can. J. Zool.  75: 1254-1261

(2) TESSIER, A. J.  1986.  Comparative population regulation of two plankton cladocera (Holopedium gibberum and Daphnia catawba).  Ecology.  67: 285-302.

(3) CHEN, C. Y., AND C. L. FOLT.  1996.  Consequences of fall warming for zooplankton overwintering success.  Limnol. Oceanogr.  41: 1077-1086

(4) BOEING, W., D. LEECH, C. WILLIAMSON, S. COOKE, AND L. TORRES.  2004.  Damaging UV radiation and invertebrate predation: conflicting selective pressures for zooplankton vertical distribution in the water column of low DOC lakes.  Oecologia.  138: 603-612.


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