Eclectic Echoes

My son and I took a ride down to the Fort Rachel Marina at the end of the street today — his first long(ish) venture on his his new bike. On the way back from the marina we stopped at the tiny public boat launch that is shoehorned between a couple of buildings.

Every time we stop there we find something interesting. A few days ago while on our evening family walk we watched a black-capped night heron stalk, catch and eat a few small fish there. This time we were disappointed until we noticed a moving rock in the shallows. It turned out to be a mating pair of horseshoe crabs (Limulus polyphemus). This is the time for them and the high tide was coming up fast, but it was really strange seeing them coming up in the boat launch. A narrow area of gravel, rock fill and silt, the female used her shell flange to clear rocks down to the silt layer, all while dragging the seaweed covered male along behind her.

Johann and I watched the pair of living fossils for about 15 minutes, talking about their ecology, biology and history all while they continued about two feet away from us. It was great since he was able to see the compound eyes very closeup, and see the hinged shell in action. It was also great to hear him tell me how they were relatives of the –now extinct — sea scorpion and that they are very special since they have survived for milions of years including the PT Dying — his name for what is known as the Permian-Triassic Extinction event in which 90% of Permian era marine species went extinct.

The picture above (poor as it is) is from about an hour later when we went back by there on our family walk. We could see about a half dozen spots where the female had cleared a “nest” to lay the eggs that will hatch out in 14—15 days. With any luck we will be able to catch a glimpse of the hatchlings in the next two to three weeks.