Haliotis jacnensis Reeve, 1846
Distribution: Ryu Kyu (Amami Oshima) to New Caledonia, Indonesia to Micronesia.
Size to 29mm. Intertidal to at least 120m deep.

The features that are constant: between the suture and the line of holes, there is a frilly area of spiral rows bearing flat scales, which are more and more spatulate as they reach the anterior margin. After this area, there is a smooth and wide field; then, the row of holes, which are always strongly tubular. On ventral side, the spire as the dorsal sculpture are visible. 55m deep, in nets, Samar, Philippines, 20mm.
The features that vary from specimen to specimen: the shape, the sheen of the nacre.
Also, the pattern and colors of the dorsum. This specimen bears some impressive spatulae,
and has a more depressed spire than the first one above. 19mm, same spot, in 2003.
Samar again, on eastern coast, by dive. 15-17mm. Brown shells are supposed to be uncommon.
Variations: the spines and scales can be displayed along helicoidal rays separated by smoother areas.
This shell is quite twisted, convex, arched, with a prominent apex.
90m deep, in tangle nets, Balicasag island, Bohol, Philippines, 20mm.
Same spot, 21mm. A variable and interesting species, whose range is not well known.
Notice the anterior margin, which is straighter than in the previous shells.
In tangle nets, at 120m deep, off east Samar, Philippines. 16mm.
White specked shells seem to be common in this species.
Spectacular specimen collected at 2-4m deep, on coral rubble.
Masbate island, Philippines. 18mm.
Shape and sculpture make this species unique in Haliotidae.
By dive, east Samar, Philippines. 20mm. This abalone was named after the city of Jacna Norte,
in the Capiz province. Capiz area is a place well known for its nacreous window-shells;
the best pieces come from here, and specialists can recognize them in few seconds.
Frilled specimen from a northern locality.
10-20m deep, on coral rubble, Cape Zampa, Okinawa. 13mm.
Two specimens from Samar. 19mm, and 29,6mm.
Original pictures © Franck Frydmann (FR).

All pics © Olivier Caro