Garra gotyla is a benthopelagic freshwater cyprinid fish native to Asia, valued for both food and ornamental purposes; nevertheless, its parasitic diseases are poorly understood. The present study investigated the presence and ecological indices (prevalence and intensity) of monogenean parasites infecting G. gotyla in Mizoram, northeast India. Additionally, the study aimed to assess the phylogenetic relationships among three closely related dactylogyrid genera: Dactylogyrus, Dogielius, and Dactylogyroides. Monogeneans were initially identified based on the comparative morphology of their sclerotised haptoral and reproductive structures, followed by BLASTn comparisons of their partial 28S rRNA gene sequences. Two dactylogyrid species, Dactylogyrus labro sp. n. and Dogielius salpinx sp. n., were recovered and are described herein as new to science. Dactylogyrus labro was found to infect all examined fish, whereas D. salpinx had a slightly lower prevalence, ranging from 76.5% to 83.3% across different sampling sites. The phylogenetic insights from these species presented in this study highlight the complex evolutionary relationships within these three genera. Further, this study provides the first confirmed molecular data for a Dogielius species, allowing for much-needed phylogenetic studies on the genus and filling a gap in sequencing data for Indian monogeneans. Since all monogeneans are potentially hazardous parasites, more studies are needed to map their diversity and effects on host fishes in this region.

Garra gotyla is an indigenous coldwater fish of the cyprinid family and has wide geographical distribution in India as well as in other countries of Asia and Africa. Induced breeding in G. gotyla was carried out successfully for the first time and an attempt has been made to document developmental stages chronologically from the first minute of fertilization, through all stages of embryonic development until the fifth day post hatching. This experiment was carried out at 22–24°C water temperature at the Directorate of Coldwater Fisheries Research, Bhimtal, India. During the breeding trial, the fertilization rate was observed as 70–75% and hatching rate was 85–90%. The mature fertilized ova were measured as 0.8–1.0 mm in diameter and the perivitelline membrane became thick soon after fertilization and formation of the germ pole. The periods taken for complete developmental stages were recorded; cleavage stage 111 min (min post fertilization (pf)), blastulation stage 580 min (pf), neurulation and segmentation 1250 min (pf) and hatching was completed after 1420 min. The sac fry was measured as 3 mm in length and took almost 3 days for complete absorption of the yolk content. The major structural and differential changes observed are in head, tail, fins, alimentary canal, rudiments of each organ and appearance of melanophore pigmentation in the whole body. The 5-day-old larvae were measured as 6 mm in length with almost every organ fully differentiated. The present study will be utilized for large-scale production of fingerlings for stock enhancement in rivers, lakes and possibilities of genetic improvement and manipulation at the embryonic stage.