Untangling the mechanisms of cryptic species coexistence in a nematode community through individual‐based modelling

Abstract

Cryptic species are morphologically identical but genetically distinct, and are prominent across numerous phyla. The coexistence of such closely related species on local scales would seem to run counter to traditional coexistence and competition theory; it has been hypothesized as a consequence of differences in their resource use or tolerances to environmental conditions. We developed an individual-based model of a community of three cryptic Litoditis marina (nematode) species, to understand how individual-level interspecific and intraspecific interactions might explain the coexistence of these closely related species. The model incorporates individuals' reproduction, competition, dispersal and resource use. Data characterizing the cryptic species (growth rates, dispersal ability, competitive interactions and responses to changing environmental conditions) were obtained from laboratory experiments involving both mono-and multispecific nematode cultures, and are used to parameterize the model. Simulation studies are used to investigate which individual-level mechanisms of dispersal and interaction lead to the characteristic population-level patterns observed experimentally. Our results highlight the key role of intraspecific competition in mediating dispersal and therefore co-occurrence of the cryptic species. The differences in dispersal also influence the response of the cryptic species to competition, a combination of factors that provides an explanation for their co-occurrence. These results provide insights into how changes in individual-level processes can be amplified to affect population-level co-occurrence.

Taxonomic and functional nematode diversity in Maldivian coral degradation zones: patterns across reef typologies and depths

“…Furthermore, the trophic functional diversity mirrored the taxonomic diversity due to the large trophic spectrum and the high adaptive plasticity of nematode buccal cavity morphologies that are closely associated with the high biodiversity of the phylum ( De Meester et al, 2016 ; Daly et al, 2021 ). Thus, a reduction in the functional diversity could, in the future, be considered an indirect measure of biodiversity loss.…”

Ancistroceruswasps (Hymenoptera, Vespidae) from the Centre of Europe: Phylogeny, cryptic species, neutral and non‐neutral markers

“…For instance, cryptic butterfly taxa show lower co‐occurrence than the congeneric non‐cryptic species (Vodă et al, 2015); cryptic congeners of fig wasps demonstrate strong evidence of competitive exclusion, whilst morphologically distinct congeners often co‐occur together (Darwell & Cook, 2017). However, there are examples of cryptic species coexistence through niche partitioning (Daly et al, 2021; Leibold, 1998; Scriven et al, 2016; Wellborn & Cothran, 2007). Occasional nesting in the same trap‐nests and in the cavities of approximately the same diameter, similar reproductive behaviour and overlapping prey and natural enemy composition imply the niche similarity of A. balticus sp.…”

Temperature-driven dynamics: unraveling the impact of climate change on cryptic species interactions within the Litoditis marina complex

“…Their coexistence primarily arises from niche partitioning, driven by subtle differences in resource use or environmental preferences ( De Meester et al, 2011 ; De Meester et al, 2015a ; Derycke et al, 2016 ; Guden et al, 2018 ; Guden, Derycke & Moens, 2021 ). Neutral dynamics ( Hubbell, 2005 ) or fluctuating environmental conditions also contribute to coexistence, as do temporal fluctuations in biotic and environmental factors ( Daly et al, 2021 ; De Meester et al, 2011 ; De Meester et al, 2015b ). Occasional episodic occurrence of specific environmental conditions can temporarily favor competitively inferior species, and facilitate coexistence with stronger competitors ( Guden et al, 2018 ).…”