Rumak D.A.1,2, Polilov A.A.1 2025. Anatomy of the springtail Hypogastrura serrata (Collembola: Hypogastruridae) // Russian Entomol. J. Vol.34. No.3: 370–387 [in English].
1 Lomonosov Moscow State University, Leninsky gory, 1-12, Moscow 119234 Russia.
2 Moscow State Pedagogical University, Kibalchicha str., 6, korp. 3, Moscow 129278 Russia.
Daria Rumak: dariarumak1@gmail.com ORCID https://orcid.org/0009-0004-8590-1832
Alexei Polilov: polilov@gmail.com ORCID https://orcid.org/0000-0002-6214-3627
doi: 10.15298/rusentj.34.3.08
ABSTRACT. While the existing data on springtail (Collembola) anatomy are extensive, they remain fragmentary in scope. To date, only one comprehensive anatomical study has documented all organ systems in a mature individual of an extremely miniature species [Panina et al., 2019]. Here, we present the first integrative anatomical analysis of the medium-sized basal poduromorph Hypogastrura serrata (Ågren, 1904) using confocal microscopy and 3D computational modeling. The medium-sized (body length 1 mm) H. serrata possesses digestive, excretory, nervous, reproductive, and muscular systems comparable to those of larger springtails. The respiratory system is absent, although other springtails have tracheae (for instance, Sminthuridae). The circulatory system of H. serrata is reduced, whereas for large collembolans, without mentioning specific genera, the presence of a heart with 2–6 pairs of ostia has been described. The digestive system of H. serrata is clearly differentiated into sections, the presence of salivary glands is shown. The excretory system consists of labial nephridia. The nervous system comprises a brain, suboesophageal ganglion, three thoracic ganglia, and fused abdominal-thoracic ganglion. Reproductive organs include paired ovaries. The muscular system contains 37 head muscles, 63 pairs of thoracic muscles, and 82 pairs of abdominal muscles. By contrast, the miniature Mesaphorura sylvatica has one reduced ovary, no salivary glands or digestive system specialization, and has muscles penetrating the brain. This comprehensive description of the medium-sized H. serrata anatomy provides a reference for studying springtail morphology, particularly the effects of miniaturization.
KEY WORDS: Collembola, anatomy, morphology, soil fauna, miniaturization.