Spikefin goby

Geographical Origin and Habitat: Discordipinna griessingeri is native to the tropical Indo-Pacific. Its geographical distribution ranges from the Red Sea and the East African coast to the Marquesas Islands, extending north to southern Japan and south to Australia. It inhabits sheltered coral reefs, lagoons, and sandy slopes mixed with coral rubble at depths of 2 to 45 meters.

Taxonomy and Morphology: Belonging to the Gobiidae family and the genus Discordipinna, this is one of the smallest vertebrate species kept in the marine hobby, with adults reaching a maximum size of just 2.5-3 cm. It features a slender body and a highly modified, flag-like first dorsal fin that it raises and lowers rhythmically.

Social Behavior: Very shy, peaceful, and cryptobenthic. It spends most of its time hovering near its chosen cave or rocky crevice. It moves with a unique, jerky swimming style, coordinating its movements with the flicking of its oversized dorsal fin. It is entirely peaceful and will not bother any tankmates.

Coloration and Sexual Dimorphism: Displays a stunning color pattern: a white or translucent body covered in red, orange, and black spots on the head and anterior section. The tall dorsal fin features white, red, and black bands, resembling a flame. There is no visible external sexual dimorphism between males and females.

Aquarium Setup: Perfect for nano-reefs and micro-reefs of at least 30-40 liters (approx. 8-10 gallons). The aquascape must provide plenty of mature live rock with micro-caves and crevices. A substrate of sand mixed with small coral rubble fragments is highly recommended to replicate their natural foraging grounds.

Diet and Feeding: Micro-carnivore. In the wild, it feeds on tiny benthic invertebrates and copepods. In captivity, it must be offered small portions of food multiple times a day. Feed high-quality live or frozen foods such as copepods, rotifers, baby brine shrimp, and finely minced mysis. They rarely accept dry foods.

Water Quality: Requires stable and high-quality reef parameters: water temperature 24-26°C (75-79°F), pH 8.1-8.4, and specific gravity 1.022-1.025. Nitrates and phosphates should be kept near zero. Keep water flow gentle to moderate, as strong currents will cause the goby to remain hidden.

Compatibility and Cohabitation: Completely reef-safe. Because of its tiny size and shy nature, it should never be housed with large, active, or aggressive fish. Ideal tankmates include other nano gobies (such as Eviota or Trimma species), neon gobies, and small commensal invertebrates like sexy shrimp.

Aquarium Breeding: Breeding in home aquariums is extremely difficult and has not been successfully achieved on a commercial scale. In nature, they lay adhesive eggs inside small crevices or shells, which the male guards until hatching. The pelagic larvae are microscopic and require specialized rotifer cultures.

Risks and Diseases: Starvation due to food competition is the greatest risk; ensure it gets fed by targeting food near its cave. They are sensitive to sudden parameter fluctuations. Due to their cryptic nature, they may hide for several days when first introduced; monitor them closely during acclimation.