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Влияние потребления пищи на функционирование пульсаторно-реверсивной распределительной системы у гидроидов – идиографический подход
The reaction of the pulsator-reversible transport system to feeding was studied in the colonial hydroid Dy-
namena pumila (L., 1758) (Leptothecata, Sertulariidae). The study is based on an in-depth individual analysis
of the movement of hydroplasm in the stolon in 3 structurally similar small colonies of D. pumila, which were
kept under the same conditions. Newly hatched Artemia salina nauplii were obtained by the dosed feeding
method in three variants: a) a proximal large maternal shoot from which the colony grew; b) 2 distal daughter
shoots near the apex of stolon growth; c) 3 middle daughter shoots. Immediately after feeding, for 90 min,
the direction of hydroplasmic flows (HPF) was recorded for every minute in all modules of the colony stolon,
noting only the direction and saturation with food particles. Then, HPF was immediately recorded using
time-lapse micro-video recording in the stolon module closest to the parent shoot for 1.5–2 h. The experi-
ments were repeated on the same colonies 20–28 hours after feeding. It was found out that after feeding in all
colonies the following indicators increase: the length and duration of HPF; maximum speed of HPF; the vol-
ume of the transferred hydroplasm by each HPF, and in total per unit of time, while the duration of the resting
phases is reduced. The results obtained indicate an increase in the intensity of colony integration after receiv-
ing a limited amount of food. At the same time, the hypothesis of the insufficiency of the pulsations of an
individual shoot to provide transcolonial HPF was confirmed. By the method of every minute scanning of the
HPF by stolon modules, it was found out that the movement of food particles in the stolon from one end to
its opposite is ensured not only by the pulsations of the shoots that received food, but also by all other shoots.
The described mechanism of HPF functioning also operates in the absence of food, although the volumes of the
transported hydroplasm are smaller. The idiographic approach made it possible to identify individual differences
for each parameter and to find quantitative difference in the results depending on the place where food was re-
ceived in the colony. Simple averaging hid these differences, which may be essential for understanding the mul-
tifactorial dependence of the functioning of the transport system in a modular organism, characterized by the
uncertainty of the combination of many equivalent processes, for example, hydranths pulsations.