Kingdom - Animalia
Leptodora kindti is the only representive of the suborder Haplopoda (Edmondson, 1959; Hutchinson,1967). The reasons that L. kindti is alone in this suborder is because of the large size that it can become, the lack of branchial appendages on its legs, the abnormal body of the organism, their winter eggs hatching in a naupliar form, and their reduced carapace (Edmondson, 1959).
Leptodora kindti body is about 98% transparent, with a large compound eye, an elongated abdomen, and has a modified carapace that just covers the brood pouch (Figure 1). According to Browman et al., (1989), Leptodora has a length range of 6 to 12 mm. The first antenna is modified for reproduction in the males (Figure 2). In the females, the first antenna is small and not very visible. The second antenna is used for swimming. Figure 3 shows L. kindti five pairs of thoracic appendages that make up the feeding basket used in feeding (Abrusan, 2003; Branstrator, 1998; Manca & Comoli 1995).
Leptodora kindti is found widely in the Palearctic regions of the world (Abrusan, 2003). This region includes Europe, Asia north of the Himalayas, northern Arabia, and Africa north of the Sahara (Merriam-Webster, 2004). L. kindti is also found the in Laurentian Great Lakes (Barbiero et al., 2001) other areas of North America and in the northern hemisphere (McNaugth, 1993).
Leptodora is found in large lakes that have planktivorous fish because of the Daphnia that is available to them, the log value of the surface area and log of the maximum depth (McNaught et al., 1993 & 2004). Most L. kindti seem to be found in eutrophic (Hellsten & Stenson, 1995, McNaught et al., 2004) meso-eutrophic (Abrusan, 2003) and, oligo-mesotrophic (Manca & Comoli 1995).
L. kindti is a predator whose diet contains mostly cladocerans (Abrusan, 2003; Branstrator & Lehman, 1991; Browman et al., 1989; Manca & Comoli, 1995). Their diet focuses on Bosmina, Ceriodaphnia, Diaphanosoma, Diaptomus, Polyphemus, Cyclop (Browman et al., 1989). L. kindti effects its prey populations by keeping the densities low. According to Browman et al. (1989), Leptodora has a feeding cycle that it always follows. The cycle is includes prey encounter, strike, capture/escape of the prey, and ingestion if captured. L. kindti ingests the prey by biting into the carapace and "plucking" up the inside of the prey (Browman et al., 1989; Manca & Comoli 1995; and Hellsten et al., 1999).
Leptodora reproduces parthenogenetically for most of the year (Balcer et al., 1984, McNaught et al., 2004). In the fall, males will start to show up in the population (Barbiero et al., 2001) and Leptodora reproduce sexually, which is important for the gene pool of the population. After mating, L. kindti females will produce resting eggs that will hatch in the spring to restart the population the next year (Balcer et al., 1984). Once the resting egg is released it will float at the water surface and eventually sink to the bottom of the lake. Young Leptodora from the resting eggs go thought a short naupliar stage before they metamorphose into the adult form (Balcer et al., 1984) (Figure 4).
Figure 1. A typical Leptodora kindti female note the shorted first antenna and a brood pouch.
Figure 2. A male Leptodora with his first antenna shown.
Figure 3. The feeding basket of Leptodora kindti, where its prey is held while it is eaten.
Figure 4. A comparison of a Copepodan nauplius (left) with a Leptodora kindti nauplius (right) (picture from Hutchison, 1967).
Abrusan, G. 2003. Morphological variation of the predatory cladoceran Leptodora kindtii in relation to prey characteristics. Oecologia. 134(4): 278-283.
Balcer, M.D., N.L. Korda, and S.I. Dodson. 1984. Zooplankton of the Great Lakes: A guide to the identification and ecology of the common crustacean species. The University of Wisconsin Press, Madison, page 49-52.
Barbiero, R.P., R.E. Little, and M.L. Tuchman. 2001. Results from the U.S. EPA's biological open water surveillance program of the Laurentian Great Lakes: III. Crustacean zooplankton. J.Great Lakes Res. 27(2): 167-184.
Branstrator, D.K. 1998. Predicting diet composition from body length in the zooplankton predator Leptodora kindti. Limno. Oceangr. 43(3): 530-535.
Branstrator, D.K., and J.T. Lehman. 1991. Invertebrate predation in Lake Michigan: Regulation of Bosmina longirostris by Leptodora kindtii. Limno. Oceangr. 36(3): 483-495.
Browman, H.I., S. Kruse, and W.J. O'Brien. 1989. Foraging behavior of the predaceous cladoceran, Leptodora kindti, and escape responses of their prey. J. Plankton Research. 11(5):1075-1088.
Edmondson, W.T. (ed.). 1959. Freshwater Biology. 2nd ed. John Wiley & Sons, Inc. New York. p 588-589 & 598.
Hellsten, M., R. Lagergren, and J. Stenson. 1999. Can extreme morphology in Bosmina reduce predation risk from Leptodora? An experimental test. Oecologia. 118: 23-28.
Hutchinson, G.E. 1967. A treatise on Limnology: Introduction to lake biology and the limnoplankton. vol 2. John Wiley & Sons, Inc., New York. p. 570.
Manca, M., and P. Comoli. 1995. Seasonal changes in size of the feeding basket of Leptodora kindtii (Focke) in Lago Maggiore as related to variations in prey size selection. Limno. Oceanogr. 40(4): 834-838.
Marriam-Webster online. www. Webster.com. Accessed on 14 October 2004.
McNaught, A.S. 1993. Suggestions of biotic niche constraints from the distrubtion of Leptodora kindti. Verh. Internat. Verein. Limnol. 25: 312-317.
McNaught, A.S., R.L., Keisling, and A. Ghadouani. 2004. Changes to zooplankton community structure following colonization of a small lake by Leptodora kindti. Limno. Oceangr. 49(4, part 2): 1239-1249.