TY - JOUR
T1 - A scanning electron microscopy study of early development in vitro of Contracaecum multipapillatum s.l. (Nematoda: Anisakidae) from a brown pelican (Pelecanus occidentalis) from the Gulf of California, Mexico
AU - Molina-Fernández, Dolores
AU - Valles-Vega, Isabel
AU - Hernández-Trujillo, Sergio
AU - Adroher, Francisco Javier
AU - Benítez, Rocío
N1 - Publisher Copyright:
© 2017, Springer-Verlag GmbH Germany.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Eggs obtained from the uteri of female nematodes, genetically identified as Contracaecum multipapillatum s.l., found in a brown pelican (Pelecanus occidentalis) from Bahía de La Paz, Gulf of California, Mexico, were used to study the early developmental stages of this anisakid by scanning electron microscopy (SEM). Egg dimensions were approximately 54 × 45 μm measured by SEM. Observation of the eggs revealed an outer surface of fibrous appearance. The newly hatched larvae were ensheathed and highly motile. Observation with SEM showed that the sheaths of the larvae were striated and revealed an excretory pore and a cleft near the anterior end of the sheath, presumably to facilitate the opening of the sheath for the emergence of the larva. The hatched larvae were placed in nutritive culture medium, where they grew within their sheath, some exsheathing completely 2 weeks later. The surface patterns of the sheath and the cuticle of the exsheathed larvae were clearly different. Although they did not moult during culture, SEM revealed a morphology typical of third-stage larvae of Contracaecum from fish, as previously observed by optical microscopy. Thus, we suggest that newly hatched larvae from eggs of C. multipapillatum are third larval stage but with sheath of the second larval stage, as occuring in other anisakids.
AB - Eggs obtained from the uteri of female nematodes, genetically identified as Contracaecum multipapillatum s.l., found in a brown pelican (Pelecanus occidentalis) from Bahía de La Paz, Gulf of California, Mexico, were used to study the early developmental stages of this anisakid by scanning electron microscopy (SEM). Egg dimensions were approximately 54 × 45 μm measured by SEM. Observation of the eggs revealed an outer surface of fibrous appearance. The newly hatched larvae were ensheathed and highly motile. Observation with SEM showed that the sheaths of the larvae were striated and revealed an excretory pore and a cleft near the anterior end of the sheath, presumably to facilitate the opening of the sheath for the emergence of the larva. The hatched larvae were placed in nutritive culture medium, where they grew within their sheath, some exsheathing completely 2 weeks later. The surface patterns of the sheath and the cuticle of the exsheathed larvae were clearly different. Although they did not moult during culture, SEM revealed a morphology typical of third-stage larvae of Contracaecum from fish, as previously observed by optical microscopy. Thus, we suggest that newly hatched larvae from eggs of C. multipapillatum are third larval stage but with sheath of the second larval stage, as occuring in other anisakids.
KW - Aquatic life cycle
KW - Contracaecum multipapillatum
KW - Egg
KW - Larval early development
KW - Morphology
KW - Scanning electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=85027877920&partnerID=8YFLogxK
U2 - 10.1007/s00436-017-5583-y
DO - 10.1007/s00436-017-5583-y
M3 - Artículo
C2 - 28823050
SN - 0932-0113
VL - 116
SP - 2733
EP - 2740
JO - Parasitology Research
JF - Parasitology Research
IS - 10
ER -