Every diver who's been to the Red Sea must have a picture with the Pseudanthias squamipinnis – Sea goldies. A very common and pretty reef fish, they are found in tropical waters among the reefs of the Indio-Pacific. They are known by many names, such as a different version of basslets, Lyretails Anthias and Scalefin Anthias. Not many people know, however, that these small, pretty fish are part of the Serraniae family - groupers and sea basses - which you would never think of by just looking at them.
The fish we mainly see on the reefs are females which are small, yellow–orange in colour with a purple line just below the eye. Adult females can be told apart from males easily, also by the length of the third dorsal fin, which is much longer in males than females. Males are often twice as long as females but rarely longer than 7cm. The female fish has a distinctive purple streak starting just below the eye. Males have a specific purplish third ray on the dorsal fin, a red patch on their pectoral fins and are more pink in colour. All Sea goldies have 10 spines, 16-18 rays on their dorsal fin, 3 spines and 6-7 rays on the anal fin.
They are protogynous hermaphrodites. When the male dies, one of the females turns into a male by undergoing a sex reversal. This process takes 2-4 weeks. They are all born female. The schools on the reefs are usually mainly females, with only a small percentage of males present who have several female harems.
They are a territorial species and tend to stay close to their home range, feeding on zooplankton around the reefs.
While they are not considered threatened, they are a very popular aquarium species, so there is a danger that the pressure will increase with increased demand from the aquarium trade.
Written by Bogna Grifin, Marine Biologist.
Photos by Ivana OK and Janez Kranjc.