Vol 103, No 9 (2024)

The results of the main studies of Z. M. Gliwicz are reviewed, highlighting his views on the evolution, biology and ecology of aquatic organisms. He was an outstanding hydrobiologist, and his scientific contributions to the development of hydrobiology were mainly related to aquatic ecology, including the prediction of the outcomes of competition between cladoceran species, vertical and horizontal migrations of zooplankton and fish, feeding behavior of fish, predator-prey relationships, interactions between adjacent trophic levels in ecosystems, and issues of evolutionary ecology. The results of Z. M. Gliwicz’s studies are analyzed in the context of the development of aquatic ecology in the late 20th to early 21st centuries.

While monitoring the Polar bear in the “Medvezh`i ostrova” (= Bears’ Islands) Nature Reserve in October 2023, a number of mainland water bodies were surveyed: the lakes “Nesolyonoe” and “Unnamed”, the Krestovaya River, the “Unnamed” watercourse on Chetiryokhstolbovyi Island, as well as the sea bay of Kolyma Bay, all in the East Siberian Sea. Representatives of zoobenthos were found in each of the water bodies studied, but the fauna was not very diverse. A total of only 7 species of benthic invertebrates were revealed in the surveyed water bodies of the Bears’ Islands Nature Reserve, of which 3 species were found in sea water: Pacifoculodes pallidus (G. O. Sars 1892) (Amphipoda), Yoldiella nana (M. Sars 1865) (Bivalvia), and Enchytraeus albidus Henle 1838 (Oligochaeta). In the water bodies feeding the Galgavaam River, 2 species from the family Chironomidae and 3 species of eurytopic Oligochaeta were recorded. Their abundance ranges from 0.20 to 1.70 thousand ind./m² and 0.10 to 3.70 g/m² biomass in freshwater bodies, vs not exceeding 0.60 thousand ind./m² and 1.90 g/m² biomass in the sea. Seasonal cohorts are formed there, 37% of which are merohydrobionts (Сhironomidae) and amphibiotic Оligochaeta, and 13% each are neritic amphipods and bivalves. The formation of seasonal cohorts is determined by a short growing season and an extended ice formation on island and mainland watercourses and reservoirs.

The growth of the unstalked crinoid Heliometra glacialis was studied based on material from the northwestern part of the Barents Sea near the Svalbard Archipelago. The calculation of the crinoid age was performed using ring-shaped markings in the their brachials. The growth rings visible on the surface of the crinoid brachials were considered as annual. The most suitable mathematical model describing the growth of H. glacialis was the Gompertz equation. The averaged limiting radius of the brachials (R_∞), according to this equation, was 1694 ± 119 microns, the exponential deceleration constant of the specific growth rate (g) amounted to 0.41 ± 0.04, and the maximum lifespan to 12–18 years.

Using scanning electron microscopy, a comparative morphological analysis of the fine structure of the guard hairs in the mummy of an adult male ancient wolf (Canis lupus ssp.) with an age of 45504 ± 150 BP, found in the late Pleistocene deposits in Yakutia, was carried out. Guard hairs selected for maximum thickness (guard I) vary significantly in different areas of the wolf’s skin in profile and metric data, and the vibrissae show a special medullary structure. The fine structure of the cellular medulla of the hair in the ancient wolf is shown to be similar to that of extant representatives of Caninae, such as the jackal (C. aureus), maned (Chrysocyon brachyurus) and red wolves (Cuon alpinus), some breeds of domestic dogs (Canis familiaris) (Akita Inu, Basset, Dalmatian, Irish Terrier, Miniature Schnauzer, Russian Greyhound, Hortaya Greyhound), and African fox (Vulpes pallida). In these species, the disordered (lacey or spongy) medulla of the thickest part of the hair shaft (“shield”) differs from the ordered (cellular, with regularly located large cavities) medulla of the fox (V. vulpes), gray (V. ferrilata) and Tibetan foxes (Urocyon cinereoargenteus), arctic fox (Alopex lagopus), corsac fox (Vulpes corsac), American corsac fox (V. velox). By this feature, it is possible to distinguish the hair of wolves and foxes, if we compare the medial part of the hair, since at the base of the hair a cellular medulla is found in some breeds of dogs (Akita Inu, Mastino Napoletano, Miniature Schnauzer, Hortai Greyhound) and corsac fox. The cuticle pattern greatly varies along the guard hair shaft, which is typical of wolves and foxes. This is especially specific in the area of the shaft in front of its thickened part, as it consists of lanceolate or diamond petal scales extended along the hair. The cuticle pattern formed by lance-shaped or diamond petal scales is quite similar in ancient and extant wolves, arctic foxes and African foxes. Yet the cuticle of the hair of many other species differs from that of wolves. Thus, such a feature as the presence of lanceolate or diamond petal cuticle on the hair is of limited importance for distinguishing between the species. We have shown that the hair of an ancient wolf in its fine structure (the thickness of the shaft, the degree of development of the medulla and its microanatomy, the cuticle pattern and its variability along the guard hair shaft) is practically not different from that of recent wolves, this confirming that the wolf as a species had already been fully formed in the Pleistocene. The fine structure of wolf hair differs from that of foxes, but has features similar to the hair of the jackal and domestic dog, this confirming the phylogenetic connections with the latter two genera.

Currently, satellite telemetry is increasingly in use in environmental research. As a result, researchers obtain a large amount of data on the use of space by animals. However, despite the perfection of modern satellite navigation and data transmission systems, reports on the positions of animals are extremely uneven. We consider here the main technical and natural factors that may influence the success of spacecraft in the “Argos” satellite system receiving messages emitted by radio beacons installed on animals. Among the natural factors when an animal is under the forest canopy, the greatest influence has been established to be exerted by the closure of tree crowns, which can be offset by the abundance of snow in the crowns after heavy snowfalls. Dense clouds have a weaker effect. Of the technical factors associated with the characteristics of flights of satellites of the “Argos” system, the success of receiving messages is influenced, first of all, by the maximum angle of elevation of the satellite above the horizon and the intensity of flights of satellites with a maximum angle of elevation above the horizon of more than 10° per unit time. This is due to the high unevenness of message receipt. At night and in the afternoon, due to a reduction in the number of satellite flights and a decrease in the altitude of their trajectories, the success of reception may decrease to 3% of the number of transmitted messages.