TY - JOUR

T1 - Self-sustaining infrapopulation or colony? Redial clonal groups of Himasthla elongata (Mehlis, 1831) (Trematoda: Echinostomatidae) in Littorina littorea (Linnaeus) (Gastropoda: Littorinidae) do not support the concept of eusocial colonies in trematodes

AU - Galaktionov, K.V.

AU - Podvyaznaya, I.M.

AU - Nikolaev, K.E.

AU - Levakin, I.A.

PY - 2015

Y1 - 2015

N2 - Trematode sporocysts and rediae reproduce by parthenogenesis, forming clonal groups in the molluscan host. It has recently become popular to consider these groups as eusocial colonies, with division of labour between rediae morphs: small “soldiers” incapable of reproduction defend the colony, while large rediae reproduce. Alternatively, clonal groups can be considered as self-sustaining infrapopulations. We tested these two hypotheses in the light of new data on rediae of Himasthla elongata (Mehlis, 1831) from snails Littorina littorea (Linnaeus) concerning ultrastructure, growth character and composition of their groups. Clonal groups under study contained rediae of different age and maturity stages: small (young) rediae, rediae with early cercarial embryos, rediae with late embryonic cercariae, rediae with fully formed motile cercariae, rediae with redial embryos and degenerating rediae. Small rediae had a reproductive organ, the germinal mass, whereas most large rediae with developing cercariae did not, w

AB - Trematode sporocysts and rediae reproduce by parthenogenesis, forming clonal groups in the molluscan host. It has recently become popular to consider these groups as eusocial colonies, with division of labour between rediae morphs: small “soldiers” incapable of reproduction defend the colony, while large rediae reproduce. Alternatively, clonal groups can be considered as self-sustaining infrapopulations. We tested these two hypotheses in the light of new data on rediae of Himasthla elongata (Mehlis, 1831) from snails Littorina littorea (Linnaeus) concerning ultrastructure, growth character and composition of their groups. Clonal groups under study contained rediae of different age and maturity stages: small (young) rediae, rediae with early cercarial embryos, rediae with late embryonic cercariae, rediae with fully formed motile cercariae, rediae with redial embryos and degenerating rediae. Small rediae had a reproductive organ, the germinal mass, whereas most large rediae with developing cercariae did not, w

KW - rediae

KW - parthenitae

KW - Digenea

KW - eusociality

KW - castes

KW - germinal mass

KW - reproduction

KW - allometry

KW - developmental arrest

KW - feeding behaviour

U2 - 10.14411/fp.2015.067

DO - 10.14411/fp.2015.067

M3 - Article

VL - 62

SP - 1

EP - 14

JO - Folia Parasitologica

JF - Folia Parasitologica

SN - 0015-5683

IS - 067

ER -