Grunion until the next tide series high enough reaches them 10 or more days later. Grunion eggs can extend incubation and delay hatching if tides do not reach them for an additional four weeks after this initial hatching time. Most of the eggs will hatch in 10 days if provided with seawater and the agitation of the rising surf. The mechanical action of the waves is the environmental trigger for hatching. The rapidity of hatching, which occurs in less than one minute, indicates it is probably not an enzymatic function of a softening of the chorion as in some other fishes.
USS Grunion Maru". Her first torpedo ran low, but despite its magnetic pistol it failed to detonate. Two more bounced harmlessly off the "Kano Maru" without exploding. However, the remaining torpedo missed its target and circled back, striking the periscope supports on the submerged submarine without exploding. The damage the torpedo inflicted, combined with a jammed rear dive plane, triggered a sequence of events that caused the loss of depth control. The "Grunion" lunged below her maximum operational depth, and at about 1000 feet would have imploded. What remained of the ship struck the seabed, breaking off about 50 feet of her