Penares is a widely distributed genus of demosponges.

[2] These sponges are irregularly massive and have a thin cortex.

Species belonging to this genus have dichotriaenes (spicules with pairs of branched rays) and oxeas (needle-like spicules with both ends pointed).

Smooth microrhabds (modified microxeas (small oxeas) or microstrongyles (small rods with both ends blunt or rounded)) form a crust in the ectosome.

Euasters (star-shaped microscleres with multiple rays radiating from a central point) may also be present.