Fish Stargazer

The stargazers are a family, Uranoscopidae, of perciform fish that have eyes on top of their heads (hence the name). The family includes about 51 species (one extinct) in eight genera, all marine and found worldwide in shallow and deep saltwaters.

Stargazer
Common stargazer, Kathetostoma laeve
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Trachiniformes
Family:	Uranoscopidae Jordan & Evermann, 1898
Genera
See text

In addition to the top-mounted eyes, a stargazer also has a large, upward-facing mouth in a large head. Their usual habit is to bury themselves in sand, and leap upwards to ambush prey (benthic fish and invertebrates) that pass overhead. Some species have a worm-shaped lure growing out of the floors of their mouths, which they can wiggle to attract prey's attention. Both the dorsal and anal fins are relatively long; some lack dorsal spines. Lengths range from 18 up to 90 cm, for the giant stargazer Kathetostoma giganteum.

Stargazers are venomous; they have two large venomous spines situated behind their opercles and above their pectoral fins. The species within the genera Astroscopus and Uranoscopus can also cause electric shocks. Astroscopus species have a single electric organ consisting of modified eye muscles, while Uranoscopus species have theirs derived from sonic muscles. These two genera within stargazers represent one of eight independent evolutions of bioelectrogenesis. They are unique among electric fish in not possessing electroreceptors, meaning that they do not use an electric sense to locate prey.

 

Stargazers are a delicacy in some cultures (the venom is not poisonous when eaten), and they can be found for sale in some fish markets with the electric organ removed. Stargazers are ambush predators which camouflage themselves; some can deliver both venom and electric shocks. Ichthyologist William Leo Smith called them "the meanest things in creation".

Uranscopidae contains the following genera:

• Astroscopus Brevoort, 1860
• Genyagnus Gill, 1861
• Ichthyscopus Swainson, 1839
• Kathetostoma Günther, 1860
• Pleuroscopus Barnard, 1927
• Selenoscopus Okamura & Kishimoto, 1993
• Uranoscopus Linnaeus, 1758
• Xenocephalus Kaup, 1858

•  
  Deepwater stargazer
  (Kathetostoma nigrofasciatum)
•  
  Northern stargazer
  (Astroscopus guttatus)
•  
  Whitemargin stargazer
  (Uranoscopus sulphureus)
•  
  Southern stargazer
  (Astroscopus y-graecum)

Timeline