Morphology of the Nauplii and Duration of Naupliar Development of the Black Sea Alien Species Oithona davisae Ferrari and Orsi, 1984 (Copepoda: Cyclopoida) in Laboratory Culture

Abstract

The paper presents descriptions, original drawings and digital photos, and also the key for identifying naupliar stages of recent invader species in the Black Sea Oithona davisae (Copepoda: Cyclopoida). Nauplii were taken from a laboratory culture originating from the offspring of O. davisae females selected from living zooplankton sampled in Sevastopol Bay. Copepods were reared under natural illumination, temperature of 21 ± 2°C, and feeding with cryptophyte culture IBSS-CrPr54 (ESD = 10.9 ± 1.4 μm) (mean concentration constituted 6 × 10³ cells mL^–1; 0.7 μg C mL^–1). The duration of the development from the first naupliar stage (N1) to the first copepodite (C1) stage was 5.3 ± 0.7 days (1 day for N1–N3, 1 day for N3–N4, and 3.3 days for N4–C1).