Electroreceptive

Finally, regarding diet and breeding, olms apparently mostly detect their prey using chemical clues and the detection of water currents but they also possess electroreceptive organs in the head and thus presumably employ electroreception. ❋ Darren Naish (2006)

The hypothesis that actinistians are the sister group of lungfishes is the most corroborated, based on five possible synapomorphies: presence of a superficial isthmal nucleus, a laminated dorsal thalamus with marked protrusion into the third ventricle, olfactory peduncles, evaginated cerebral hemispheres with pronounced septum ependymale, and electroreceptive rostral organs. ❋ Unknown (2005)

One lineage led to the ray-finned fishes, or actinopterygians, and they've kept a weak electroreceptive system to this day. ❋ Wired UK (2011)

About 500 million years ago there was probably a predatory marine fish with good eyesight, powerful jaws and sharp teeth roamed the oceans, sporting a lateral line system for detecting water movements and a well-developed electroreceptive system to sense predators and prey around it. ❋ Wired UK (2011)

These flask-shaped, electroreceptive organs - well known and familiar to anyone who knows sharks - are distributed across the White shark's snout and around its jaws, but while many sources show the organs in cross-section, I've never actually seen their contents before. ❋ Unknown (2010)

The presence of large bifurcating canals within the bones of the ichthyosaur rostrum has led some to speculate that ichthyosaurs had enhanced tactility in the snout, and it's even been proposed that ichthyosaurs might have had electroreceptive abilities (that is, that they could detect the electrical signals given off by muscular activity in other animals). ❋ Unknown (2009)

Last I read the hammerhead shape was due to an increase in ampullae and the higher electropore density over a wider area giving them an increased electroreceptive capability. ❋ Unknown (2009)