Saturday, August 6, 2016

Gargantuan Gastropods

All summer long, the tabloids and gossip columns are full of Malibu celebrity sightings, but here's a really big celebrity (or possibly a sea-lebrity) that's been overlooked: 
Aplysia vaccaria, the California black sea hare, a mild-mannered sea slug that has the distinction of being the world's largest gastropod. Eat your heart out, Orlando Bloom. Unless otherwise noted, all photos are © 2016 S. Guldimann.

Were you aware, dear reader, that the Malibu coast is currently playing host to large numbers of the world’s largest gastropod? While that sounds alarming like the plot of a 1950s B movie, this celebrity among slugs is a peaceful vegetarian, despite a passing resemblance to that movie monster favorite, The Blob.

Although it bears a distinct resemblance to Hollywood's favorite invertebrate horror,  A. vaccaria is mostly harmless. Image: Wikipedia

While the California brown sea hare, Aplysia Californica, is a regular tidepool resident in Malibu, this year, its much larger relative, Aplysia vaccaria—the black sea hare—is turning up in large numbers. No one at the Malibu Post can remember seeing more than one or two black sea hares. It's unclear if the vast number showing up this year is related to the unusually warm water or if other factors are in play.

Brown sea hares are smaller and usually a lighter color than their giant relative. Both species graze on kelp, which they chew up with a rasp-like tongue called a radula. Sea hares get their name from their rabbit ear-like appendages—actually scent organs called rhinophores.

Brown sea hares can grow to be impressively large for a slug, often measuring more than 15 inches from nose to tail.  A. vaccaria, however, can grow to be more than three feet long and weigh as much as 30 pounds. That’s one big slug. The largest specimens rarely turn up in the intertidal zone, but this year’s Malibu crop of A. vaccaria is still impressive, resembling a football in size and shape.

This unfortunate slug was left high and dry by the receding tide. However, sea slugs have adapted to the extreme conditions of the intertidal zone and can survive several hours out of water even in bright sunlight during low tide. The holes in the rock near this slug's head measure about an inch across, giving an idea of the creature's size.

Sea hare eggs look exactly like noodles, but probably would not be pleasant to eat. Both California species contain toxins from their algae diet that make them inedible to almost everything except lobsters—the garbage crew of the sea—and green anemones, which appear to be immune. There's a type of Australian sea hare that is so toxic that dogs have died after coming into contact with it. California sea hare species are much less potent, but it's a good idea not to handle them and to keep dogs away from them. Brown sea hares can release a purple dye that is a skin irritant. Black sea hares appear to depend on their terrible toxic taste for defense.

Sea hares are usually observed grazing on seaweed in tidepools during low tide, like this California brown sea hare, or waiting for the tide to rise while stranded, blob-like, on the beach, but they can also "fly" through the water with their wing-like parapodia—literally "foot wings."

There's actually a third giant gastropod on the loose in Malibu: the giant limpet, which is really another type of sea snail and not a true limpet at all. This species, Megathura crenulata, is the only known member of its genus, making it a monotypic genus. 

M. crenulata can grow to be nearly a foot in length. It may not be much to look at, but compounds in the blood of this primitive snail apparently hold promise as a cancer treatment. According to a 2011 article in the Journal of Immunology Research, "Keyhole limpet haemocyanin (KLH) appears to be a promising protein carrier for tumor antigens in numerous cancer vaccine candidates." 

After a sort of gastropod goldrush in the early 2000s that ran the risk of pushing this rare animal to the edge of extinction, M. crenulata is now being raised via aquaculture techniques.

Megathura crenulata, the only known member of its genus, lives only off the coast of California. The blood of this primitive snail species has become a key ingredient in vaccine research, but the burgeoning demand for the giant limpet blood could push this poorly understood and increasingly rare species to extinction. 

Here's a side view of M. crenulata, suggesting a very old person shuffling along under a large umbrella, and revealing the creature's true snail nature. Sea hares also have a shell, but it is internal and vestigial.

Sea hares are also important for medical research. According to the Aquarium of the Pacific's sea hare page, the California brown sea hare may not have a lot of brain wattage, but it has "the largest neurons in the animal kingdom, making it possible to identify individual nerve cells that are responsible for specific behaviors. They have been and are being used extensively in studying memory, behavior, and learning."

Humans may not find sea hares or giant limpets lovely to behold, but there's more to Malibu's giant gastropods than meets the eye. 

A football-sized specimen of A. vaccaria waits for the incoming tide on the beach at Little Dume.

Tuesday, August 2, 2016

Living with Lizards

One of The Malibu Post's resident Western fence lizards consents to pose for a portrait. Unless otherwise noted, all photos are © 2016 S. Guldimann

It was dusk and the faint glow of a smartphone screen illuminated the face of a small girl intent on capturing an imaginary animal in the street in front of The Malibu Post. The girl's father, hovering nearby, called instructions: "Wait until there's a green circle, that's it!" The Pokemon was successfully captured and the pair moved on. I felt a certain kindred feeling. I've spent the last several months attempting to track down a full collection of creatures, too, but while my hunt was for real world creatures, several proved every bit as elusive as any legendary beast.

Anyone who lives within the boundaries of the Santa Monica Mountains National Recreation Area has lizards among their nearest neighbors. They sun on the rocks in the garden, or zip across the driveway. Sometimes they show up uninvited in the house where they may end up mummified under the couch or on the cats' menu, but mostly the reptile world and the human world occupy the same space largely unnoticed by the inhabitants of each world. That's unfortunate, since human activity can inadvertently take a terrible toll on lizards, and because lizards are beneficial and interesting and worth a closer look. However, just because they often live among us doesn't mean they're easy to find.

The Western fence lizard is the most common reptile in Malibu. It is quite happy to take advantage of garden features like rocks and fences. Those fantastically long toes and claws on the hind feet enable the fence lizard to almost effortlessly climb vertical surfaces like tree trunks.

Seven lizard species can be found in the Santa Monica Mountains. Four of those species can be found even in urban gardens, but the Western fence lizard is far and away the most commonly seen reptile. This small cousin of the iguana lives alongside humans, successfully surviving in even the smallest gardens and yards, but also abundant in the wild. 

Fence lizards are beneficial garden residents. They feast on creatures humans regard as pests, including mosquitos, ticks, scorpions, centipedes, beetles and spiders.  Fence lizards are, in turn, a key food source for everything from hawks and roadrunners, to gopher snakes and larger lizards. 

The Western fence lizard's Latin name, Sceloporus occidentalis, let's you know that this is the Western spiny lizard. Up close, the fence lizard's back scales resemble a pinecone. 

Fence lizards that don't end up on the menu of some larger animal can reportedly live for as much as five or six years. 

The metallic blue stripes on the fence lizard's underside give this species its other popular name: the blue-belly. This is an adult male. Females have much fainter markings.
Some Malibu gardens are also home to another iguana relative, the side-blotched lizard, Uta stansburiana. This small elegant lizard comes in a surprisingly wide range of colors and may have spots, stripes or, sometimes, no markings at all. 

Some Malibu residents have this beautiful lizard in their gardens. At first glance, the side-blotched lizard closely resembles the fence lizard, but this species has brighter, lighter markings and a scale pattern that is much less spikey than the fence lizard's.

Visitors to Point Dume State Park or Malibu Bluffs Park Open Space are almost guaranteed to see the colorful side-blotched lizard going about its business of hunting ants and other small invertebrates. Like the fence lizard, they are an important food item for numerous other species of birds, reptiles, and mammals. Unlike the fence lizard, they are not strong climbers and prefer to stay close to the ground.

The side-blotched lizard's scales resemble a George Seurat painting. 
Fence lizards and side-blotched lizards are active, lively lizards. They dart around the garden in pursuit of insects, sun themselves on rocks, squabble with their neighbors, and often lounge in the middle of the driveway. However, there's a third common Malibu lizard species that many Malibu residents have never seen, although it also lives in our gardens. 

The Western skink, Eumeces skiltonianus, is a sleek, secretive lizard that stays close to the ground, hiding under rocks and dead leaves, and even tunneling underground when the soil is moist.

We rescued this unfortunate Western skink from the cat, who apparently heard me lamenting that I needed a good photo of a skink and decided to present me with one—quite a feat for an indoor-only cat. This little guy clearly had another recent close call, its tail has detached and is just beginning to grow back. Juvenile western skinks have a bright blue tail. Adults like this one are a sedate cinnamon color.

The Western skink has a taste for sow bugs and moths. Possibly because of its secretive ways, it is longer lived than other local species, reportedly surviving for as much as 10 years when conditions are right.

The fourth common garden lizard is the fierce and robust Southern alligator lizard. Alligator lizards are not closely related to true alligators, but apparently no one bothered to explain that to them. They are fierce, grumpy and aggressive. They swallow other lizards whole, devour mice and small birds and have a remarkably painful bite for something that doesn't have teeth.

This is the undisputed Malibu lizard king, the alligator lizard. I photographed this nearly foot-long behemoth at Malibu Bluffs Park. The alligator lizard gets its name from its gator-like looks, but it isn't a close relative of its namesake. This is, however, a fierce and voracious beastie, that will swallow smaller lizards whole, and has been known to go after birds, rodents, and people's toes. 

This juvenile alligator lizard strayed into the bathroom and had to be rescued before it became a cat treat. Juvies are smooth and bronze-colored, and lack the distinctive scale pattern of the adults. Here at The Post we find best way to rescue a lizard from the house is to herd it into a bucket or wastepaper basket, cover the container with a newspaper or book, and cart lizard and container to a safe place for release back into the garden. Many lizard species are territorial, so it's a good idea not to take them too far from their point of entry into the house. Screen doors can help cut down on the number of uninvited reptilian houseguests.

Our fifth native lizard may also be at home in the garden, but it is almost never seen, and when it is it gets mistaken for either a small snake or a large earthworm. 

The legless lizard, Anniella pulchra, spends its life almost entirely underground, tunneling through sandy soil for grubs and worms. We've never seen one here at the Malibu Post, but a new subspecies turned up recently near a runway at LAX, of all places, so it iss a distinct possibility that this small secretive lizard is quietly living its life just a few feet away from where I sit writing this post.

Here's a photo of 
A. pulchra courtesy of Wikipedia Commons. Although it looks like a snake, it is a true lizard, equipped with a detachable tail-tip to fool predators into thinking they've caught the whole animal. It also has eyelids and can blink, something snakes can't do.

Mystery marks in the sandy soil at the Point Dume Headlands may indicate the presence of legless lizards, but this observer has never seen one at work.

Here's a closer look at A. Pulchra. This photo was taken by Marlin Harms in Los Osos, CA, and appears on Wikipedia.

The remaining two local lizard species are, unfortunately, increasingly rare. The coastal whiptail was already rare when I was a child, but there was a time when this colorful lizard was abundant throughout the area.

Frederick Hastings Rindge, who purchased the entire Malibu Rancho in 1892, had this to say about the coastal whiptail lizard in his 1898 book Happy Days in Southern California:

The long pipe-stem lizards sunned themselves near by, but they are not very harmful; they are so called because, if struck by a stick, their tails fly into as many pieces as a pipe stem when broken on the pavement. The common little lizards are harmless, sometimes being even used for pets. 

I do not like to recall the remembrance of a lady in Saint Augustine, Florida, I once knew, who had such a creature for a pet, feeding it regularly and taking it in her hand. 

A Californian I have known who would catch them, put them on his shoulder, and let them run at will over his back. These things are told to ward off fears of poison. The big pipe-stem fellows, however, I will not vouch for.

We wouldn't vouch for them either, because this lizard has some formidable claws. There are two Southern California whiptail species. Ours is Aspidoscelis tigris stejnegeri, the tiger whiptail. There's also an orange-necked whiptail, that lives in San Diego County.

We had to go into the back country of the Santa Monica Mountains to find this beautiful beast. The coast whiptail was once common in Malibu. Frederick Hastings Rindge talks about this species in Happy Days in Southern California. Habitat loss in Malibu has left it on the California species of special concern list for this area. The whiptail is a medium-sized lizard with powerful legs that enable it to move fast. It also has formidable claws, and despite the dramatic yellow and black markings it has mastered the art of not being seen.

Can you spot the lizard? Finding lizards can be like a cross between Pokemon Go and Where's Waldo. 

Most whiptails are in a fearsome hurry, but this one was surprisingly cooperative about being photographed.

We had to go on an expedition to the back country to find whiptails for this article. This species is a California Species of Special Concern, and can only be found in a few locations in the Santa Monica Mountains. It was May, and we witnessed a strange and wonderful thing, the mating dance of the whiptail, which involved a sort of fencing match, followed by Sumo wrestling. By now, the eggs will have hatched, and a new generation of whiptails will be embarking on the dangerous life of the lizard.

Coastal whiptails engage in a complex mating dance. This photo was taken in Triunfo Canyon in May on 2016.

We never expected to find a legless lizard for this article, but I had high hopes for finding the seventh species, the coast horned lizard, Phrynosoma blainvillii, also known as Blainville's horned lizard.

When I was a child, horned lizards were common in Malibu. I vividly remember the first one I ever saw. It was at the Paradise Cove Mobile Home Park. My friend's mother called us over to see it just outside the door of their Airstream. I was four years old, and enchanted. It looked exactly like one of the plastic dinosaurs I played with at home.

The Malibu Post never succeeded in tracking down a horned lizard for this article, but here's a wonderful image of the dinosaur-like Blainsville's horned lizard. Photo: USGS/Chris Brown

The horned lizard remained a personal favorite, but even so, I couldn't tell you when it began to disappear. Habitat loss and the mass invasion of the tiny Argentine ant, which displaced the native ants this lizard feeds on, are to blame for this this species ending up on the California Species of Special Concern list.

That's why it's ironic to me that after months of hunting for the once plentiful horned lizard to photograph for this blog post, I finally spotted one at Malibu Bluffs Park Open Space, right where the City of Malibu is planning to build new baseball diamonds.

The encounter left me with the uncomfortable feeling that  the day may be coming all too soon when this species will be joining the dinosaurs that it resembles, and that Malibu, in an effort to provide recreational facilities for the community, will be unintentionally hastening its demise.

Pokemon Go has taken the country by storm. A player in New York made headlines last month for reportedly "collecting them all."  It's great that the game is getting people out of doors, but here at the Malibu Post we could wish that our own real live amazing creatures are as valued and appreciated as the imaginary ones currently so highly prized.