Estimation of trophic niches in myrmecophagous spider predators

• Published in: Scientific reports Vol. 10; no. 1; p. 8683
• Main Authors: Dušátková, Lenka Petráková, Pekár, Stano, Michálek, Ondřej, Líznarová, Eva, Symondson, William O. C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26-05-2020; Nature Publishing Group
• Subjects: 631/158; 631/158/2452; 631/158/856; Animals; Ants - genetics; Body Size; Callilepis; Callilepis nocturna; Callilepis schuszteri; Cluster Analysis; Content analysis; DNA - chemistry; DNA - metabolism; Estimates; Experiments; Gnaphosidae; Humanities and Social Sciences; Insects; Invertebrates; Laboratories; multidisciplinary; Myrmecophagy; Niche breadth; Nomisia exornata; Polymerase Chain Reaction; Predators; Predatory Behavior; Prey; Science; Science (multidisciplinary); Specialization; Species; Spiders; Spiders - genetics; Spiders - physiology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-65623-8

Among spiders, taxonomically the most diversified group of terrestrial predators, only a few species are stenophagous and feed on ants. The levels of stenophagy and ant-specialisation vary among such species. To investigate whether stenophagy is only a result of a local specialisation both fundamental and realised trophic niches need to be estimated. Here we investigated trophic niches in three closely-related spider species from the family Gnaphosidae (
Callilepis nocturna
,
C. schuszteri
,
Nomisia exornata
) with different levels of myrmecophagy. Acceptance experiments were used to estimate fundamental trophic niches and molecular methods to estimate realised trophic niches. For the latter two PCR primer sets were used as these can affect the niche breadth estimates. The general invertebrate ZBJ primers were not appropriate for detecting ant DNA as they revealed very few prey types, therefore ant-specific primers were used. The cut-off threshold for erroneous MOTUs was identified as 0.005% of the total number of valid sequences, at individual predator level it was 0.05%. The fundamental trophic niche of
Callilepis
species included mainly ants, while that of
N. exornata
included many different prey types. The realised trophic niche in
Callilepis
species was similar to its fundamental niche but in
N. exornata
the fundamental niche was wider than realised niche. The results show that
Callilepis
species are ant-eating (specialised) stenophagous predators, catching mainly Formicinae ants, while
N. exornata
is an ant-eating euryphagous predator catching mainly Myrmicinae ants.