Postembryonic development oh hard jaws (trophi) in a species belonging to the Brachionus plicatilis complex (Rotifera, Monogononta) : a morphometric analysis
Articolo
Data di Pubblicazione:
2006
Citazione:
Postembryonic development oh hard jaws (trophi) in a species belonging to the Brachionus plicatilis complex (Rotifera, Monogononta) : a morphometric analysis / D. Fontaneto, G. Melone. - In: MICROSCOPY RESEARCH AND TECHNIQUE. - ISSN 1059-910X. - 69:4(2006), pp. 296-301.
Abstract:
The presence of hard jaws (trophi), with species-specific shape and size, is a taxonomic
feature of Rotifera, a group of microscopic metazoans. Since trophi are used to discriminate
among species, it is important to know whether these structures change in taxonomically important
ways during postembryonic development. Using both SEM and optical images, we analyzed more
than 100 individuals of a single clonal lineage of a monogonont rotifer, Brachionus plicatilis, in order
to describe body and trophi development after hatching. Body size, expressed as lorica width and
length, was isometrically related to age of the animals only during preadult stages. Trophi size,
expressed as length of the different parts, was unrelated to either age or body size. Therefore, trophi
elements do not grow after hatching in B. plicatilis. Despite the dimensional invariance with age,
some differences in trophi size among individuals of the same clone were recorded. No difference in
left–right asymmetry of the trophi was shown; the asymmetric elements of the trophi named rami
consistently had the right ramus longer than the left. This constancy is in contrast to the reported
trophi asymmetries in bdelloid rotifers, in which left–right asymmetries are not constant within clonal
lineages. In conclusion, we suggest that also trophi size, constant within the analyzed clone, may
be used as an additional taxonomic feature to help in the discrimination of taxa within the B. plicatilis
complex of cryptic species.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Morphology; Postembryonic development; Scanning electron microscopy
Elenco autori:
D. Fontaneto, G. Melone
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