California Spiny Lobster: fully-armored all-terrain vehicle

Photo credit: Mark McDermott

Photo credit: Mark McDermott

There he was, the California Spiny Lobster, and I swear he was staring at me. No matter which way I walked those black beady eyes followed me, he was the Crustacean Mona Lisa, only better. His long antennae wavered about feeling the water acting as sensors.

But the most impressive characteristic of this particular lobster was his sheer size. According to the little plaque posted at the Cabrillo Aquarium he is 13 pounds and an estimated 40 to 50 years old and I immediately dubbed him Tank.

Not because he lives in a tank, but because he seriously looks like a small tank or fully-armored all-terrain vehicle. One that is ready for battle, armed with two gunners in front, encased with heavy plated armor and ready to march.

The California Spiny Lobster, or Panulirus interruptus, hails from the phylum Arthropoda, the broader scientific classification including insects, spiders and crustaceans. And the lobster does share traits with its more distant bug relatives, a segmented body, an exoskeleton (the more accurate name for its body armor) and jointed limbs.

But the California Spiny Lobster is so much more than a glorified water bug. For starters it’s bright red or as a report by the U.S. Fish and Wildlife Service describes “alternately red and olivaceous.” Olivaceous? To clarify, the California Spiny Lobster is a wonderful red with hints of olive and orange mixed in.

This bold coloring gives the California Spiny Lobster an extraterrestrial quality, as if it is Mars’ sole survivor, the last remnant population to successfully escape the dusty red planet for Earth’s blue ocean bottom millions of years ago and where it continues to lurk today.

But this red protective shield comes at a great cost, as it is completely inflexible and in order to grow lobsters must cast off the shell periodically and develop a new shell underneath the old one. As Trevor Corson describes in his book The Secret Life of Lobsters, “In the weeks prior to molting, the lobster’s skin cells enlarge and secrete the beginnings of an entirely new shell underneath the old one.”
While this is a natural process for lobsters, the actual moment of transitioning into the new shell is a complicated and traumatic experience. The lobster starts by pumping in seawater, intentionally placing pressure on the old one to force it off.

Corson gives a quick biology 101 recap explaining that as an invertebrate, every rigid feature of the lobster’s body is part of the exoskeleton, including teeth in the stomach that crush food. So to ditch the old shell a lobster has to ditch the old stomach teeth, which Corson sums up in this hair raising description: “The lobster must rip out the lining of its throat, stomach, and anus before it is free of the old shell. Some die trying.”

All I can say is yikes! That sounds gruesome, making this the perfect opportunity to move on to more merry lobster topics.

Lobsters are famous for their claws, but it turns out that characteristic applies to the famous east coast lobster, Homarus americanus, commonly known as the American lobster and found on dinner plates across the nation.

Without claws, the California Spiny Lobster is much more approachable, almost downright friendly. It turns out that California Spiny Lobsters also find each other more approachable and spend time together, socializing on the sea floor.

UC- Santa Barbara PhD candidate and researcher, Carla Guenther explains: “Spiny lobsters are gregarious and love to hang out in crevices in large numbers while East coast lobsters are highly territorial and aggressively fight off intruders, even peeing to mark their territory.”

So while the East coast lobsters battle, the California Spiny Lobsters follow the social patterns of the Los Angeles club scene. They’re out all night foraging, hopping from one rave to the next and crashing in dens (rock crevices) during the day to sleep it off.

Since the lobster industry has never been as prominent in California’s economy, much less is known about the California Spiny Lobster compared to its East coast cousin, Guenther explained. Scientific data on the California Spiny Lobster is sparse, especially behavioral observations that could enlighten us on the purpose of the Spiny Lobster’s cocktail lounge gatherings or business meetings.

“It looks like they are hanging out like hippies in a commune, but they could be creating a gang to defend an area and each other,” said Guenther. “We don’t really know who hangs out with who, if there is any size relationship or why they pack so densely in dens.”

For now these assemblies remain a mystery, but thankfully knowledge about the “birds and the bees” is much more extensive and fascinating.

“They basically do it in the missionary position and the male flips the female onto her back and the male lays his spermatophore on her,” Guenther said. Awesome, is my response. It turns out that the spermatophore is actually a gelatinous substance holding sperm that hardens into a consistency closer to silly putty.
But of course I must know more, how does this really work?

Guenther explained that the male’s fifth (and last) pair of legs is unique and constructed with a built-in ridge. For lobster sex, the fifth legs come together creating a funnel, like two sides of a slide. The spermatophore is delivered between the third and fourth set of the female’s walking legs. So there is no true intercourse, it’s closer to a UPS delivery service where the male lobster rests his important package of sperm on the female lobster’s stomach area instead of on the doorstep.

Once the female lobster successfully receives the spermatophore, it hardens into the tougher silly putty consistency allowing her to carry it around with her until she is ready to produce eggs. Corson compares this to a fanny pack, but let’s just be clear this is a fanny pack carrying sperm, not a fanny pack carrying your cash, cell phone and keys.

Guenther said the common lingo for the hardened spermatophore is the patch. So let’s go with that.

When the female lobster is ready to take reproduction to the next level, she “uses her walking legs to open the patch, scratches at it and fertilizes eggs that are released through an adjacent opening,” said Guenther. “The process starts at the patch so she’s moving her legs from her chest to her back legs to her tail. So it looks something like knitting, it’s a fluid process.”

After fertilizing 300,000 to one million eggs through this well-orchestrated flurry of motion, the female lobster stores them under her tail attached to her pleopods, or swimmerets, which are small, soft paddle -like structures. The female lobster carries the eggs around with her for about three months, “walking with her tail tucked underneath to protect the eggs until they hatch,” Guenther said.

This entire process is simply amazing and I now have a new found respect for lobsters, the magnificent all-terrain vehicles of the deep. Their trials and triumphs are extreme, yet they keep on keeping on. To Tank, the California Spiny Lobster living at Cabrillo Aquarium, and to lobsters everywhere, I admire your tenacity and determination.


  1. J Napoli says

    This is a real favorite. Love the analogy to the LA club scene. Also great that you interview other experts, too. Your blog is quite unlike most things out there!


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