Change of pace: the spiny lobster

Although the lobsters pictured above are not the spiny lobster variety, they represent this delicious crustacean that we call a lobster, and just as a changeup from the heavy scientific approach on this blog site to date, here are some facts/information, part 1, about these "bugs." Most of the information is specific to the spiny lobsters, especially the California Spiny Lobster; there are more than 25 different kinds/species of spiny lobsters in the world oceans, primarily in the tropical waters. This is the type of lobster without a large claw, which is only representative of the one species of the Maine Lobster.

How old is a lobster? Although estimates of age vary widely, it is generally believed that a just-legal lobster (a lobster about 10 1/2-11 inches long, slightly less than one pound in weight) is about 7-8 years old. Once hatched from the egg, the lobster goes through at least 11 different larval stages while swimming around in the water column. They are small and transparent during the 6-9 months spent in these stages. The last 1-2 larval stages are spent on the bottom, among the surf grass (most of us divers call this eel grass) in very shallow waters. The lobsters are greenish in color then, and they rapidly transform into sub-adult forms. Within the first year, these sub-adults molt (or cast off their external shells) up to 20 times, adding on a little size with each molt. During the second year of life, the molting frequency decreases to 10 or so, 3-4 times during the 3rd year, and 1-2 times per year by the 5th year of life. Thus, a legal-sized lobster only molts once each year; the larger ones probably only molt once every other year or even less frequently. A 10-pound lobster has been estimated to be anywhere from 20-50 years old.

What happens to a lobster when a diver breaks off a leg or antenna and fails to capture it? Given that the lobster is not fatally incapacitated by the loss of such a structure, it can re-grow the lost leg or antenna. However, it takes a minimum of 3-4 molts to fully replace a leg or an antenna.

How does a lobster reproduce? We will discuss the external anatomical differences between males and females in the next posting. Mating between fully-mature males and females (probably 4-5 year-old lobsters) occurs during the winter and early spring months (January-March); during this process, the male deposits a sperm-containing packet to the underside of the female, in the area between the bases of her last 3 walking legs. This packet contains countless numbers of sperm and has the consistency of soft putty when first deposited. It is creamy colored at that time. Within a short period of time, this sperm packet hardens and blackens. The female containing this packet is referred to as "plastered." The spawning, or laying of eggs, by the female actually takes place in the spring and summer months (April through August). The bright orange/reddish eggs are laid through the opening at the base of the 3rd pair of walking legs, picked up and transferred to the fan-shaped swimmerets on the bottom side of the tail by the 5th pair of walking legs, until up to 500,000 eggs are laid by a single large female. She then faces upcurrent, rubs the bottom side against a rock until the sperm packet breaks open, releasing the sperm, which then drift back to fertilize the eggs. The female lobster, called a "berried" female now, seeks shelter in isolation (usually in fairly shallow water) and remains relatively quiescent until the eggs hatch in a few weeks.

What does a lobster eat? A lobster is a nocturnal forager, meaning that it feeds actively at night or in periods of reduced illumination. It is known to be an omnivore, in that it eats virtually anything. Its diet has been found to consist of such diverse organisms as worms, other crustaceans or shrimp-like animals, snails and other soft-bodied animals, sea urchins, virtually any species of fish, kelp, coralline red algae, and surf grass.

Looking at things from a slightly different perspective, there are several predators that feed actively on lobsters. The chief ones are the octopus and several species of fish (moray eels, sheephead,black sea bass).

Do lobsters stay in one home (homing) or do they migrate? All evidence indicates that the California Spiny Lobster engages in both types of behavior. A single lobster has been tagged and reobserved in exactly the same den for more than 2 years in the San Diego-La Jolla Marine Ecological Reserve; this same study noted that males exhibit a stronger tendency to home, or stay in one hole or in adjacent dens, than females. Many veteran divers will reveal the knowledge of the existence of a large "bull" lobster in their "secret spot" over long periods of time, but they will not tell you where that "secret spot" is located. Whether this "bull" is the same one or not over the entire period is of little consequence to you; what you want to do is to follow this mossback diver to the secret spot so that you can see for yourself and make appropriate observations.

Although the evidence does not indicate the presence of mass migrations of the California Spiny Lobster in the manner of Panulirus argus, the Florida lobster, there is nevertheless a general movement of the population offshore during the winter months and inshore during the summer months. One of the curious observations noted in the survey study in the SD-LJ Marine Ecological Reserve was the increase in the total population numbers in a given area from 1976 to 1977. Closer examination of the data revealed that this increase was due primarily to an influx of the younger, smaller lobsters. Presumably, one possible explanation for this movement is the increased rainfall and associated bad weather/water conditions that would serve to "drive" the smaller lobsters out of the shallow waters into the slightly deeper waters of the study area.

How does a lobster see? The lobster's eyes, at the end of stalks protected by the large head spines, are made up of many facets and are thus similar to the insect's compound eye. Therefore, it is doubtful that the lobster enjoys clear, sharp binocular vision; rather, it sees a mosaic pattern (which is much like what you see when you take a color-vision test). The lobster, then, is able to perceive quick movements which breaks up the mosaic and is relatively insensitive to slow movements. This can be turned to your advantage in catching these elusive animals. Make your movements deliberate and slow, rather than jerky and rapid, until you are close enough that you know your speed is greater than the lobster's getaway velocity.

What is the status of the lobster fishing industry? From a high take of nearly a million (933,449 pounds) pounds in 1946, the lobster annual catch has declined to a mere 200,000 pounds in recent years. As is true in any activity, a disproportionately small part of the fishermen take a major share of the lobsters, indicating that experience and know-how are valuable assets in this business. Although the statistics for 1979 are not complete yet, casual conversations with lobster fishermen inform us that this year's take will not differ significantly from the previous few years; in other words, fishing still is not great. It appears that overfishing is the guilty culprit in this decline, although it is not clear what the influence of the increased number of sport divers has been to the lobster population. Recent cases of the illegal traffic in "short" lobsters bodes ill for the future of the lobster population's recovery. Respecting the minimum size limit for any commercial/sport fishery is of utmost importance in the management of that species. Although it is just as greedy to take too many lobsters as too small ones, the damage to the population base on a long term aspect is much more severe with the incursion into smaller sizes. Any fishery is set up so that the species enjoys at least 2 years of breeding before becoming susceptible to take in the legal fishery; thus, the taking of smaller specimens may lead to the danger of total elimination of the breeding population, which, of course, is disastrous to that population's sustenance.

Now that you have caught a lobster, how do you fix it for dinner? There are many excellent cookbooks on the preparation and cuisine of lobsters. One excellent reference, not just for lobsters but for all sorts of seafood, is Bottoms Up Cookery. This fascinating book is available in most dive stores, as well as the Scripps Institution of Oceanography Aquarium book store. It details the cleaning of the lobster, or of eel, or squid, or octopus, and also offers several enticing and delectable recipes.