Acta Parasitologica, Vol. 51, No. 2, 2006, 100-106 Ana J. Alarcos(1,3)*, Veronica A. Ivanov(2,3) and Norma H. Sardella(1,3) - Distribution patterns and interactions of cestodes in the spiral intestine of the narrownose smooth-hound shark, Mustelus schmitti Springer, 1939 (Chondrichthyes, Carcharhiniformes)
(1)Laboratorio de Parasitologia, Departamento de Biologia, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar
del Plata, Funes 3350, 7600 Mar del Plata; (2)Laboratorio de Helmintologia, Departamento de Biodiversidad y Biologia Experimental,
Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon II, piso 4, (C1428EHA)
Buenos Aires; (3)Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Argentina
*Corresponding author: jalarcos@mdp.edu.ar
ABSTRACT
The distribution patterns and the cestode species interactions within the spiral intestine of 20 specimens of Mustelus schmitti
from coastal waters off Mar del Plata, Argentina were studied. Six cestode species were found: Tetraphyllideans Calliobothrium
barbarae, C. australis, C. lunae and Orygmatobothrium schmittii, diphyllidean Echinobothrium notoguidoi and trypanorhynch
Eutetrarhynchus vooremi. The most common number of parasite species per host was 3. Brillouin's diversity index ranged from
0.1 to 1.2. Berger-Parker dominance index indicated that C. barbarae was the dominant species, followed by O. schmittii and
C. australis. Calliobothrium barbarae, C. australis and O. schmittii presented a broad distribution along the spiral intestine,
whereas C. lunae, E. notoguidoi and E. vooremi showed a more restricted niche breadth. In general, the Renkonen's index
showed no evidence of niche overlap in the range of distribution of the different species. In most of the infracommunities,
intraspecific aggregation was stronger than interspecific aggregation, indicating that competition may play a little role. The
distribution patterns of the Calliobothrium specimens concurs with the predictions of attachment sites for Calliobothrium
species made by previous authors.
KEY WORDS: Cestodes, Mustelus schmitti, spiral intestine, interactions, distribution patterns