Parasites alter interaction patterns in fish social networks

Social networks influence the spread of parasites through populations. Although we know how parasites are transmitted as a product of social interactions, we have a limited understanding of how social networks are affected by parasites over time. Host–parasite interactions and the networks they form, are typically examined as static networks, and while topological descriptions at a specific time point are useful, both behaviour and the infection process are dynamic. By monitoring replicate populations of Trinidadian guppies (Poecilia reticulata) daily before and during infection with the ectoparasite Gyrodactylus turnbulli, we show how parasitism drives social network dynamics. Specifically, infected individuals increased their connections in networks affected by parasitism. In contrast, uninfected control shoals showed no change in network metrics. The structure of subnetworks (motifs) and networks, however, did not change in response to infection status. These findings provide further..., Host-parasite system
Trinidadian guppies (Poecilia reticulata) were laboratory-reared descendants of wild-caught stock from the Lower Aripo River, Trinidad, in 2012. Fish were initially housed at the University of Exeter, before transfer to Cardiff University in 2014 to be maintained in 70 L dechlorinated water tanks under standard conditions of 24 ± 0.5°C on a 12 h light: 12 h dark photoperiod (Lights on 07:00–19:00). Fish were fed daily on Aquarian® Tropical fish flakes, subsidised with freshly hatched Artemia salina and adult Daphnia magna. Aquaria were checked weekly for fry, which were transferred to rearing tanks from which female fish were isolated at 8-12 weeks. Only female guppies (n=120) were used due to their greater propensity to shoal than males (Griffiths & Magurran, 1998), but also to avoid the confounding effects of male courtship behaviour and sexual interactions on parasite transmission and social network structure.
For experimental infections, we used the isogenic..., # Data from: Parasites alter interaction patterns in fish social networks

Dataset DOI: [10.5061/dryad.vmcvdnd47](10.5061/dryad.vmcvdnd47)

## Description of the data and file structure

Behavioural experiments were conducted on 20 guppy shoals in a controlled aquarium environment to study social interactions and parasite transmission dynamics. Each shoal of six marked females was observed daily for 10 days, with 15 shoals receiving experimental parasite infections and 5 serving as controls. Fish interactions were recorded to build daily directed, weighted social networks, capturing in- and out-degrees, betweenness centrality, and transmission-relevant motifs. Infection intensity and network metrics were generated from these data to assess how social structure influences parasite spread.

### Files and variables

#### File: ind_infect.csv

**Description:** The infection data for individuals within the experimental systems.

##### Variables

* shoal: The unique shoal identifier (categori...,