Physical: The spotfin killifish is one of several killifish found in the Barnegat Bay. At just under 2 in (5 cm), they’re the smallest killifish species. Males have 10-14 dark vertical stripes on their body and a black spot on their dorsal fin, from which the species gets its name. They have less stocky bodies than striped killifish. Females resemble juveniles, with grey-green or olive green color and faint or no stripes.
Habitat: Their range spans from Georgia up through Massachusetts. They live in shallow brackish water with muddy bottom, including small and poorly oxygenated pools in saltwater marshes. They hide in soft sediment or in clumps of S. alterniflora (smooth cordgrass). Since they live in the intertidal zone between dry land and permanently submerged habitat, they can tolerate extreme variation in temperature, salinity, and depth.
Feeding: Spotfin killifish are omnivores. Adults feed on insects, plant detritus, and zooplankton, while juveniles feed on smaller zooplankton and nematodes.
Breeding: The spawning season lasts from mid-April to mid-August. Females lay eggs in clusters of 2-4, or as just a single egg. They hatch within 12-16 days.