# High-Throughput Sequencing-Based Assessment of Intestinal Parasitic Infections in Economically and Medicinally Valuable Captive Tokay Gecko (Gekko gecko) and Chinese Blue-Tailed Skink (Plestiodon chinensis)

## TL;DR

This study uses high-throughput sequencing to assess intestinal parasites in two commercially farmed reptiles, finding host-specific infection patterns and highlighting the need for better health management.

## Contribution

The study introduces high-throughput sequencing as a novel method for parasite surveillance in economically valuable reptiles, revealing host-specific infection patterns.

## Key findings

- Cryptosporidium was detected exclusively in Chinese blue-tailed skinks, showing a highly significant host-specific pattern.
- Co-occurrence network analysis revealed significant positive associations between parasites and gut fungi and protozoa.
- Six pathogenic genera were identified, with varying prevalence rates between the two reptile species.

## Abstract

Captive reptiles raised for economic and medicinal purposes are frequently exposed to intestinal parasites, which can compromise their health and reduce reproductive success. Because their economic value largely derives from medicinal use, they are described as reptiles with medicinally driven economic value. In this study, we examined fecal samples from two commercially farmed species, the tokay gecko (Gekko gecko) and the Chinese blue-tailed skink (Plestiodon chinensis), using high-throughput sequencing to profile their intestinal eukaryotic communities and identify pathogenic parasitic genera. The overall parasite infection proportion was 57.1% (12/21) in Chinese blue-tailed skinks and 42.9% (9/21) in tokay geckos. Notably, Cryptosporidium was detected exclusively in Chinese blue-tailed skinks, with its prevalence showing a highly significant difference between the two hosts (p = 5.32 × 10−5, Fisher’s exact test). Certain parasites displayed positive associations with fungi and other gut microorganisms, suggesting potential ecological interactions that may influence the course of the infections. Together, these findings highlight the host-specific nature of parasite infection patterns and underscore the importance of monitoring parasite dynamics as part of health management strategies in reptile breeding systems.

Captive reptiles bred for economic and medicinal purposes are often susceptible to intestinal parasites that undermine their health and overall farm productivity. In many regions, their economic value largely derives from medicinal use; accordingly, they are described as reptiles with medicinally driven economic value. In this study, we applied high-throughput sequencing to characterize gut eukaryotic communities and assess parasite prevalence in tokay geckos (Gekko gecko) and Chinese blue-tailed skinks (Plestiodon chinensis). Across both host species, six pathogenic genera were identified: Cryptosporidium (P. chinensis: 57.1%, 12/21; G. gecko: 0%), Eimeria (P. chinensis: 14.3%, 3/21; G. gecko: 0%), Oswaldofilaria (P. chinensis: 0%, G. gecko: 4.8%, 1/21), Strongyloides (P. chinensis: 14.3%, 3/21; G. gecko: 19.1%, 4/21), Spironucleus (P. chinensis: 14.3%, 3/21; G. gecko: 9.5%, 2/21), Spauligodon (P. chinensis: 0%, G. gecko: 14.3%, 3/21). Among these, Cryptosporidium exhibited a striking host-specific pattern, occurring exclusively in Chinese blue-tailed skinks (Fisher’s exact test, p = 5.32 × 10−5). Principal component analysis (PCA) demonstrated clear host-associated segregation along PC1, which accounted for 58.2% of total variance. Furthermore, co-occurrence network analysis revealed significant positive associations (all p < 0.01) between parasites and other eukaryotes, particularly fungi and protozoa. Collectively, these findings underscore the value of high-throughput sequencing for parasite surveillance in reptile farming and point to the importance of integrated diagnostic approaches and enhanced biosecurity measures for maintaining animal health.