Lymphocystis Disease in Endemic Aotearoa New Zealand Bully ( <i>Gobiomorphus cotidianus</i> )

We detected lymphocystis disease virus (LCDV) for the first time in an Aotearoa New Zealand freshwater environment, from an individual common bully, toitoi, Gobiomorphus cotidianus (Eleotridae). Dinah's bully, Gobiomorphus dinae, and Kaharore bully, Gobiomorphus mataraerore, also exhibited gross nodular lesions on the fins but were not sampled. Histopathology of G. cotidianus nodular lesions revealed hypertrophic lymphocystis cells showing thick hyaline capsules and intracytoplasmic inclusion bodies. DNA tested positive for lymphocystis disease virus using primers targeting the major capsid protein (MCP) gene. It tested negative for genotype I of LCDV (synonym of species LCDV1) and genotypes LCDV II and LCDV III (synonyms of unclassified LCDV species from Korea and Japan) and was most closely related to genotype LCDV IV (synonymous with unclassified LCDV-RC and SB98Yosu species found in China, Taiwan, and Korea). This suggests the involvement of a potentially novel New Zealand variant. This study provides the first LCDV gene sequence from New Zealand, which contributes to global efforts to identify lymphocystis disease in the wild. Some bully species are amphidromous, which presents opportunities for LCDV transmission in freshwater, estuarine and marine environments.