Aim The torrential hill streams of eastern Himalayan region represent a unique lotic water ecosystem. The fish population inhabiting this regionaredesignated as habitat specialists. Being good indicator of different environmental factors, haematopoiesis can be considered as an important component in survival strategy of such characteristic fish. So, the aim of the present study was to perform quantitative and qualitative evaluation of developing blood cells in the head kidney of two such habitat specialist fish species of River Mu rti- Garra gotyla gotyla and Garra annandalei. Methodology Garra gotyla gotyla and Garra annandalei we re collected from three different sites of river Murti selected along decreasing altitudinal gradient and different habitat type. Tissue imprint technique and haematopoietic efficiency determination method we re employed for qualitative and quantitative analysis of haematopoietic cells. Cell cycle phase distribution of nuclear DN Aof head kidney cells were determined by flow cytometry. Results Eleven types of hematopoietic precursors and mature cells in erythroid and lymphoid lineage at different developmental stages were identified and documented through cytological description and morphometry in head kidneys of both the species. The erythroid lineage was dominant over all other lineages with relatively less storage forms and more young and mature eiythrocyte population which was about 55.73% and 47.74% of the whole haematopoietic components studied in Gaira gotyla gotyla and Garra annandalei, respectively. The flow cytometry analysis of the head kidney cells of both the species according to their Forward scatter (size) and Side scatter (granularity) properties revealed two distinct populations corresponding to small agranular and large granular cells. The percentage distribution of such cells by flow cytometry corroborated with the observation under light microscopy. Cell cycle analysis and erythropoietic efficiency of head kidney also revealed significantly high maturation rate of developing blood cells in Garra gotyla gotyla than Garra annandalei. Interpretation The differential pattern of erythropoiesis might indicate its functional significance reflecting differences in the survival strategies and habitat selection of Garra gotyla gotyla and Garra annandalei.