Sydney Leatherjackets

 

Leatherjackets are a highly specialised fish. The scales have been modified in the extreme to a tough and often spikey skin, The difference between males and females is frequently dramatic.This sexual dimorphism is very pronounced in some of the Leatherjackets.

 

 
Toothbrush Leatherjacket Mosaic Leatherjacket
The Toothbrush Leatherjacket is one of the most incredible examples of sexual dimorphism in the fish world. Males and females are so different that they were once thought of as different species. The Brown algae in the background in Ecklonia kelp. Algae are covered comprehensively in my Marine Biology course. The juvenile mosaic Leatherjacket clings on to fan sponges during the long nights.This sponge is home to the Rostanga sea slugs and the amazing Cling Goby cleanerfish from Sydney.
Anglerfish Leatherjacket
The Sydney Half Banded Perch having a rendezvous with a Grey Botany Bay Anglerfish. Leatherjackets such as this Yellow Fin Lj have a huge dorsal spine which can lock in place to wedge themselves into a crack at night or to prevent being eaten.Their rough and tough skin often has spines on each fish scale.