In this study, some biological characteristics of the invasive moon crab, Matuta victor, which has recently entered the waters of the northeastern Mediterranean, Türkiye, were investigated for the first time. The study was carried out seasonally on sandy bottoms at 0.5-3 m depths along Karataş (Adana, Türkiye) coasts between 2020 -2021. A total of 364 crabs were obtained, 93 females (27 ovigerous), 270 males and one juvenile. The carapace width of female crabs ranged between 27.49-49.30 mm with a mean of 41.55±4.01 mm. The carapace width of male crabs ranged between 21.28-66.70 mm with a mean of 49.15±8.97 mm. Mean carapace length measurements in females and males were 26.83±2.52 mm and 32.71±5.85 mm, and the mean total weights were 8.18±1.99 g and 16.27±7.30 g, respectively. The male:female ratio was 2.16:1. Morphometric relationships indicated negative allometric growth for females, males, and both sexes. Ovigerous females were obtained in all seasons except the winter. The female crabs with carapace widths that ranged between 35.31-48.84 mm and a mean of 41.97±3.29 mm had a mean fecundity of 36822.04±29745.9 eggs.