Earthworms are iteroparous organisms with indeterminate growth, i.e. they continue to increase in size throughout their life and after completion of sexual development. Terrestrial oligochaetes vary greatly in size. Depending on the species, adult earthworms can reach between 10 mm and 3 m in length and between <1 mm and >25 mm in width, with most being of length 5-15 cm. Among the more than 7000 species described to date, very few (~20) reach lengths greater than 1 m. The longest earthworm on record is Amynthas mekongianus, which is found in the mud banks of the Mekong River in Southeast Asia and which reaches almost 3 m in length. It is about the same size as Megascolides australis, the ‘Giant Gippsland Earthworm’. These atypically giant earthworm species remain a scientific curiosity in terms of their biology, but they cannot be considered cases of gigantism. Gigantism occurs when organisms are much larger than normal or exhibit excessive growth. Earthworms obtain energy from the organic matter on which they feed, and their growth mainly depends on the quality of the resource and on the species, as well as on food availability, environmental factors, which can directly or indirectly affect growth by modifying food availability, and other factors such as competition. This is particularly evident in earthworms, which display indeterminate growth and large species-dependent variations in size. The biology, life cycle and growth and reproduction rates of Eisenia fetida (Savigny 1826) and Eisenia andrei (Bouché 1972), the earthworm species most commonly used in vermicomposting and vermiculture, have been widely reported. Here we present details of the enormous growth of individual specimens of Eisenia andrei and Dendrobaena hortensis reared under particular culture conditions and fed a special diet. Individuals almost 20 times the average weight of individuals of the species have been obtained. Possible explanations for this interesting phenomenon are discussed.

A previous study involving whole genome sequencing of the white shark suggested unique molecular evolution accounting for gigantism and the enhanced longevity of sharks including positive selection of dozens of protein-coding genes potentially involved in genome stability. We performed a reanalysis on some of the genes and identified serious flaws in their results. In this short article, we scrutinize one of the serious problems we identified, report other concerns, and point out a potential bias in analyzing iconic shark species in general.

Boreal forests are one of the largest stores of carbon on Earth, and two-thirds of them are located in Siberia. Despite the fact that these forests have a significant influence on the global climate, they continue to remain understudied. Chernevaya taiga is a unique example of a highly productive Siberian boreal ecosystem. This type of forest is characterized by a series of unique ecological traits, the most notable of which are the gigantism of the perennial herbaceous plants and bushes, complete lack of moss cover on soil surface, and the type of soil it grows on, notable for its particularly high rate of decomposition of vegetative remains and low humic acid content. Abundant rainfall actively washes out nutrients from the top layers of the soil, but its fertility level remains very high. In fact, based on the existing data, it is twice as high as that of fertilized agricultural lands. In some ways the conditions within this type of forest closely resemble those observed in tropical rainforests. Microbiota associated with soil and plants represent an integral part of an interconnected system and contribute significantly to productive processes in soils. Its impacts on the environment require further study, since it could lead to discoveries that will help improve soil fertility without harming the natural environment.