Expert Reef Lobster Care Tips :
These normally reclusive lobsters can actually be colorful and interesting to watch.
courtesy to : www.fishchannel.com / By Scott Michael
Reef lobsters make wonderful aquarium pets. They sport attractive colors, and while somewhat reclusive, they can be very interesting to observe. We’re going to examine the biology and captive care requirements of these cool crustaceans.
The least common aquarium lobsters belong to the family Palinuridae, which includes the spiny and slipper lobsters. These animals tend to get larger (especially the spiny lobsters) and can be very destructive in a reef aquarium. They have been implicated in damaging clams, snails, hermit crabs, sea urchins and fish tankmates.
The reef lobsters (genus Enoplometopus) are fascinating aquarium inhabitants that can be housed in smaller tanks. This is E. daumi. Photo by Scott W. Michael
The most common spiny lobster encountered in the aquarium trade is the blue spiny lobster (Panulirus versicolor). The juveniles are dark blue and white, and have very long white antennae. Juveniles are attractive and may seem benign, but this animal can reach a length of about 15 inches and is a threat to both ornamental invertebrates and fish tankmates.
Many aquarists are tempted to add a small blue spiny lobster (Panulirus versicolor) to their home aquariums, but this animal gets large and is very destructive. Photo by Scott W. Michael
The reef lobsters have been in a state of taxonomic confusion for many years. In the past, they were placed in the families Nephropidae or Axiidae, but in 1988 a new family was created for the group: Enoplometopidae. This family contains a single genus, Enoplometopus, which contains 11 species. Reef lobsters differ from spiny lobsters in that they have larger, more well-developed pincers (chelae) on the first pair of walking legs. These pincers are used in defense, dueling with rival consexuals and possibly in prey capture. When intimidated, they will lift their large pincers and direct them toward the threat. The second to fifth pairs of legs have small "false” pincers.
Unlike spiny lobsters, reef lobsters also have groups of sensory hairs all over their exoskeleton. They are also smaller than their spiny cousins, none exceeding a length of 5 inches. The reef lobsters have a well-developed beak, called a rostrum (which is absent or small in spiny lobsters), large black eyes (they seem to have fairly good eyesight) and long, threadlike antennae. These are colorful animals, sporting various shades of orange, purple, red and white.
You can differentiate male reef lobsters from females if you place them in a clear specimen container and hold them up so you can see the underside of the abdomen and thorax. In females, there is a padlike sperm receptacle on the thoracic sternum (that is, between the last three pair of legs). The receptacle can be as big as a pea, but it oblong with a split in the middle. The first pair of legs under the abdomen (this pair of abdominal legs are referred to as pleopods) exhibit differences between the sexes. In males, these appendages are larger and are leaflike at the far end, while in females, they are thin and threadlike. There is also sexual dimorphism in the position of the gonopores (small genital openings). In females, the gonopores are found at the base of the third pair of legs, whereas in males they are present at the base of the fifth pair of legs. The gonopores are small, but can be seen with a magnifying glass.
While they are referred to as lobsters, members of the genus Enoplometopus are more closely related to freshwater crayfish than they are spiny lobsters (such as this Panulirus). Photo by Scott W. Michael
Most of the reef lobsters occur in reef environments and are very secretive. They spend their time (especially daylight hours) deep in reef crevices and caves. Occasionally, they may make diurnal forays to their refuge opening. After dark, reef lobsters venture into adjacent, open areas to forage. Quantative data is lacking on what they forage for, but it is likely that they forage for worms, other crustaceans and possibly small fish and other benthic (bottom-dwelling) invertebrates. At least some species (e.g., Enoplometopus occidentalis) are fairly site-attached; you can find them in the same crevice day after day for extended periods of time.
The slipper lobster (family Scyllaridae) differs from the Enoplometopus in having a flat body and shovel-like appendages. Photo by Scott W. Michael
Most reef lobsters are also deep-dwelling animals, living at depths of 250 to at least 900 feet. The three species most often encountered in the aquarium trade (discussed here) are more abundant at lesser depths (less than 100 feet).
Three species are regularly encountered in the aquarium trade. Enoplometopus daumi is pinkish or orangish-pink overall, with darker vertical stripes, and many white spots on the abdomen and some on the dorsal surface of the carapace. It is exported from the Philippines and Indonesia. Enoplometopus debelius has a light base color (in some cases, gray to almost white) and is adorned with small purple or purplish-pink spots all over the body. This species ranges from Indonesia (where most are collected) east to Hawaii. Enoplometopus occidentalis is orangish-red overall, with white spots on the abdomen and a few scattered dots on the carapace. This species is wide-ranging, occurring from the Red Sea to the Hawaiian Islands.
A Dubious Reputation :
The reef lobsters are durable aquarium inhabitants that will thrive in a well-maintained aquarium and will even survive in a tank subjected to some neglect. One key to enjoying these animals is to place them in a tank where you will actually be able to view them on occasion.
When it comes to compatibility, reef lobsters have a rather sordid reputation. Some suggest they are highly predatory on ornamental invertebrates and fish. Others say they are rather passive reef tank inhabitants. This may be a case of individual variation, not species-specific differences. I also think it’s a function of how often the aquarist feeds the tank (more on this later).
Personally, I have found that the Enoplometopus I’ve kept were not a threat to fish neighbors or to most ornamental invertebrates. I have kept them with gobies, blennies, dartfishes, small demoiselles and small wrasses (including species that bury in the substrate at night).
That said, I do believe these crustaceans are a threat to fish if they are underfed. To give you an example, I believe a reef lobster I kept in a 57-gallon reef aquarium picked off some of its fish neighbors as a result of not being fed enough while I was on vacation. (I cannot be sure this is the case, but everything had been fine in the fish-invert community for months until I left for two weeks and had a neighbor feed the tank infrequently and not "target feed” the lobster.) These lobsters may also subdue and eat nano-gobies at night while the fish are quiescent, but my reef lobsters have never assaulted shrimpgobies or their pistol/snapping shrimp (Alpheus spp.) partners. I have seen a reef lobster investigate the opening of a shrimpgoby-alpheid shrimp burrow only to be "shot” at by the resident pistol shrimp. Pistol shrimp have an enlarged claw they can snap shut rapidly. The concussion that results from the sudden closure can do damage to other organisms (especially smaller creatures) — it could not hurt the lobster, with its armored exoskeleton, but it may frighten it. My curious reef lobster quickly retreated.
The author has successfully kept pairs of harlequin shrimp (Hymenocera picta) with reef lobsters — but remember these shrimp need live sea stars to eat if they are going to survive. Photo by Scott W. Michael
I do believe I have lost smaller ornamental shrimp to reef lobsters. For example, I had a group of unidentified cleaner shrimp (Lysmata sp.) that gradually disappeared, and while I never saw the lobster attack and eat one of the shrimp, I blamed the reef lobster because I never found a corpse and all the shrimp disappeared at night. I have kept (and still do keep) reef lobsters with harlequin shrimp (Hymenocera picta) without incident. Some sources (see references) suggest that they are threat to hermit crabs, crabs and shrimp (these crustaceans are more vulnerable to attack just after they molt). Reef lobsters are not a threat to corals, sea anemones or other sessile invertebrates. I had a larger specimen that attacked and ate an ailing flame scallop, but the mollusk was so far gone that it could not completely shut its valves and hence was vulnerable.
Because these animals are well-armed and armored, they are immune from predation from all but the largest carnivores. However, morays, large wrasses, triggers and puffers may be able to thwart the defenses of reef lobsters. Like all crustaceans, these animals are more vulnerable to predators during the molting period, and may hide away for a week or more during this time. Always use a specimen container to capture these animals, as the strong spines on the abdomen and tail have a tendency to snag in standard fish nets.
Most Enoplometopus are very aggressive (there is some evidence that E. daumi may be slightly less aggressive than the other two readily available species; see Holthuis, 1991). When reef lobsters encounter one another, they charge forward with their pincers raised. The problem with reef lobsters is that their behavioral repertoire does not include any submissive behaviors. The two lobsters will attempt to grasp the pincers of their adversary, and if they achieve this, they will begin to rapidly flex their tails. This enables them to twist the appendage of their opponent — the goal of reef lobster battles is to damage the rival’s pincers.
Spiny lobster. Photo by Scott W. Michael
If a reef lobster is injured, it will retreat, but the winner does not ease off. Instead it will press its attack until the subordinate lobster leaves the area. In captivity, the losing lobster cannot get away. The winner will continue to attack the other lobster until it dies. It’s likely that Enoplometopus will attack other genus members, as well. Members of the same sex will fight, but you can keep heterosexual pairs in tanks of 100 gallons or more.
Feeding and Reproduction :
Not only are reef lobsters beautiful (most are either red or purple with lighter or darker spots), they are also excellent scavengers. Make sure you get some meaty food to them, especially if you don’t feed your reef tank very often. They will also eat plant material, including dried algae sheets. You can target feed your reef lobster by squirting (using a turkey baster with flexible tubing food attached) into the hole where the crustacean typically hangs out. If you keep it with smaller fish, I suggest target feeding several times a week. If well fed, it’s not uncommon for the younger reef lobster to molt about every six weeks or so (this molting interval will become longer as the animal attains maximum length).
If you keep a pair in a large enough tank, they will typically spawn. Because these animals are nocturnal and spend most of the daytime deep in dark crevices, they have developed the ability to recognize a member of the opposite sex through touch. There are other nocturnal crustaceans, like the banded coral shrimp (Stenopus hispidus), that recognize gender by touching their antennae together. In contrast, reef lobsters lie their antennae along the side of the body when they encounter each other, apparently to prevent damage to these important sensory structures. If you place two of these animals together, they will rush toward one another as if they are going to fight.
Fertilization only occurs just after the females molt. Apparently, chemicals exuded during molting attract a nearby mate. The male gently flips the female on her back and the mating occurs for about two minutes, at which time the male deposits sperm on the receptacle between the female’s thoracic sternum. The female then expels numerous small eggs (about 0.5 mm in diameter) from the gonopores and deposits them on the pleopods. She uses these appendages to oxygenate the eggs (she will wave them back and forth), and removes debris and dead eggs with her hind legs. The female becomes antisocial, chasing off the male if he approaches, until the eggs hatch (this occurs at night, usually in about six days). The larvae are difficult to raise, so there’s little chance you will see captive-raised Enoplometopus in the marine trade anytime soon.
I hope this information will be useful to those of you who have considered purchasing one of these cool crustaceans. Do not hesitate to add one of these animals for your reef tank, but be aware there this some risk that they will eat ornamental crustaceans and small fish. Happy lobster-watching!
Cushing B. S. and E. Reese. 1998. "Hawk-like aggression in the Hawaiian red lobster, Enoplometopus occidentalis.” Behaviour 135:863-877.
Debelius, H. 1999. Crustacea Guide of the World. Ikan, Frankfurt, Germany. Pp. 321.
Holthuis, L. B. 1991. FAO Fisheries Synopsis: FAO species catalogue. "Marine lobsters of the world.” 13:125. Rome, Italy. Pp. 292.
Lougher, T. 2007. What Invertebrates? A Buyer’s Guide for Marine Aquariums. Interpet Pub. Surrey, England. Pp. 208.
Spiny Lobsters: Unusual Marine Inverts
courtesy to : wwwtfhmagazine.com / Author: Edward Adam Jackson
Large and demanding, spiny lobsters are not for the casual aquarist, but they make beautiful, fun, and long-lived aquarium residents for those willing to dedicate a setup to them.
Rock and spiny lobsters of the genusPanulirus aren’t generally recommended for the mixed reef/invertebrate or fish-only display (with some exceptions), but given a dedicated tank and proper care, these animals are quite worthy aquarium specimens that can make fun displays. Just be sure to know what you’re getting into before making a purchase, as these lobsters are often the victim of impulsive buying habits.
Spiny Lobsters :
Over 20 different species belong to the genus Panulirus, and their distribution ranges quite widely. Species of this genus can be found in a wide array of climates, including but not limited to the tropical Pacific Oceans in Hawaii, temperate Pacific waters such as California, and even as far as the Atlantic subtropics in the Caribbean.
The main feature that differentiates Panulirus lobsters from other lobsters is the lack of the large claws (chelipeds) found in their cousins such as Homarus spp. and Astacoidea spp. Not to be outdone,Panulirus lobsters boast a large pair of walking legs in place of the missing claws. They also harbor a pair of antennas that are specialized for sensory perception to help them detect and adjust to their surroundings. These are normally kept alongside the body and extended only when in use.
Panulirus are in large part nocturnal, taking refuge in caves, crevices, and overhangs during the day and feeding and hunting during dusk, early morning, and nighttime hours. Though individuals can be found relatively close to each other at times, lobsters are generally intolerant of each other, excluding a very interesting, seemingly ceremonial gathering that occurs in an Atlantic species, P. argus.
Not a Genus for Casual Aquarists
I find it very sad to walk into various fish stores and see multiple spiny lobsters. As hardy as members of this genus can be, they simply are not suited to the average home aquarium. The list of compatible organisms is quite short and arguably non-existent for some individuals. Furthermore, most aquariums are too small to house these organisms, some of which reach sizes upward of 2 feet. These overgrown lobsters are quite indiscriminate in what they will eat and should be the poster child for that popular hobby phrase “opportunistic omnivore.” Any invertebrates, sessile or motile, are at risk, and the clumsy movements of these animals can topple unstable rock fixtures or decorations. And yes, even slower, smaller fish are at some risk with a large lobster in the tank. They should by no means be classified as social or reef safe.
As with most lobsters, rock lobsters are quite messy eaters and big waste makers. Since they are crustaceans, it’s necessary to keep dissolved organics to a minimum. Given their large size, eating methods, and waste production, a lobster’s bioload on a system could easily rival that of any similarly sized or larger predatory fish, or one that has a high metabolism. The nutrient accumulation caused by these animals alone can cause the balance of smaller, unprepared systems to take a negative turn.
I admit that this causes Panulirus spp., and lobsters in general, to seem undesirable when there are other smaller, more compatible crustaceans that can coexist with other invertebrates and fish. A tank with lobsters would certainly need to be designed and maintained with them as the centerpiece, something many aquarists just aren’t willing to do.
Many species of spiny lobsters are placed in the “best left in the ocean” category. Living in Southern California, one of my largest complaints is the fact that many stores offer local specimens, which are temperate. If you plan to place a temperate species, such as the California spiny lobster (P. interruptus), in tropical water, you are condemning it to death.
Animals like P. interruptus do best in temperatures around 60°F—temperatures above 65° are pushing it. In fact, while diving mostly off of Catalina Island during the summer of 2011, most temperatures for the month of May varied from 58° to 64°. The highest I measured was 66°, and that was during high noon in a tide pool less than 5 feet deep.
If you decide to keep one of these temperate species, a water chiller is a must. These units can be quite expensive. Temperate tanks also tend to constantly form condensation on the outside due to the ambient temperature in the room typically being higher. To counteract this, a thicker and preferably acrylic tank would be the best way to go. As such, it would probably be in your best interest to keep tropical specimens. The following list includes the members of the genus that aquarists are most likely to come across.
Ula (Panulirus marginatus)
P. marginatus, known locally as ula, is endemic to Hawaii. The species itself is highly protected, as are all the animals in Hawaii, and it will be quite difficult to attain one. Any commercial gathering is currently illegal; only hand-caught ula over certain lengths are legal.
Having said that, they are beautiful creatures that are very hardy when given the right care. As with most lobsters, they are quite voracious eaters and will easily consume any invertebrate or plant life housed with them. Tank lighting and rock arrangement will need to be thought through very carefully, as this animal is a dedicated nocturnal reef denizen. This species reportedly attains lengths of 18 inches, though 12 inches is much more common.
Blue Spiny Lobster (P. versicolor)
In my experience, the blue spiny lobster is the most widely available species in the aquarium trade. It’s also a tankbuster at a potential 24 inches. They are much more predictable and agreeable than their cousins, especially as juveniles. For the most part, they are fairly timid and calm—at smaller sizes, it is not unheard of to hear of them cohabiting in mixed reef tanks even with other lobsters, causing no harm. Though they are more timid than most lobsters, they can still be quite boisterous and destructive as adults, so my recommendation stands to keep this species and all spiny lobsters in dedicated aquaria.
As it grows, the blue spiny lobster will begin feeding indiscriminately with a seemingly bottomless stomach. It should be fed various meats of marine origin. Blue spiny lobsters appreciate overhangs and caves in which to hide, though it is commonly seen burrowing pits into the substrate to take refuge. Overall, P. versicolor is quite hardy, has lots of personality, and in general is just a fun pet. As it adjusts to captive life, it can be coaxed into exploring its environment during daylight hours.
Ornate Spiny Lobster (P. ornatus):
The ornate spiny lobster has quite a large distribution in comparison to some of its cousins, ranging from the Red Sea all the way down to Africa, and is a common sight in many Western Pacific islands. Quite boisterous and very bold, it will ruthlessly defend its territory. Though lobsters are destructive in general, the ornate takes the meaning to a whole new level. This species is yet another tankbuster, with a potential length of 24 inches. It is best kept as a single specimen.
Spotted Spiny Lobster (P. guttatus) :
The spotted spiny lobster is quite a handsome specimen and, aesthetically, my favorite of the genus. This is one of the few spiny lobsters you will find in association with sessile invertebrates. It’s quite common to see the spotted spiny lobster taking refuge among overhanging coral rather than a rocky cave. It also appears to be somewhat more reserved and cautious than other spiny lobsters, beingquite difficult to coax out in daytime hours. Its potential size is somewhat more manageable at 20 inches, though 12 and 16 inches are common.
Hawaiian Blue Lobster (P. penicillatus):
The blue spiny lobster, or Hawaiian blue lobster, (P. penicillatus) is another species that is routinely available in the aquarium trade. Though not indigenous, it’s most common in the Hawaiian Islands and falls subject to the same laws as P. marginatus. The laws are just, as this animal has been irresponsibly overfished.
Its behavior is very similar to that of P. versicolor, but this species comes in a slightly more agreeable size, with adults rarely growing to 15 inches in length. It’s less prone to scavenging organic matter than the other members of the genus and is more likely to seek out live prey—something worth noting.
Caribbean Spiny Lobster (P. argus):
Commonly known as the Caribbean or Florida spiny lobster, P. argus, as its name suggests, hails from the subtropical Atlantic, even as far as the Gulf of Mexico. This too is quite an attractive species, with a striped body that flaunts brown, gray, and even some yellow pigmentation.
It’s more predator than scavenger, commonly hunting sea urchins, mollusks, other crustaceans, bivalves, and even the occasional fish. Studies of carcasses have revealed a significant amount of vegetable matter in the stomach, so some sort of plant matter should supplement its mostly carnivorous diet.
Like P. ornatus, this species can be quite bold and aggressive. Tankmates are once again not advised, though similarly sized specimens do appear congregating in reef overhangs, so it may be possible to care for multiple individuals in the same system. As I mentioned before, P. argus also engages in another unique social collaboration: The ceremony starts with a small gathering in shallower waters just before the dreaded storm season. Once the individual congregation gains numbers, the animals march together in a very orderly line into deeper water. Logical guesses lead scientists to hypothesize that the march into deeper water is a response to the heavy tropical storm systems that pound the area for a significant duration of the year, and that the sudden social behavior of these quite anti-social creatures is a defensive mechanism. It is quite an odd but very eerily beautiful sight I hope to see one day in person .
California Spiny Lobster (P. interruptus) :
The California spiny lobster is a temperate species with a range along the coast in the Eastern Pacific Ocean. It hails from as far north as the Bay Area down past Baja California to the gulf of Tehuantepec, Mexico. Its channeled or interrupted slots and grooves go across the abdomen in the tail section, something that is not as prevalent in other spiny lobsters (which have uninterrupted grooves or lack them completely).
It is in large part nocturnal, emerging at the end of dusk to feed on echinoderms such as the California purple sea urchin (Strongylocentrotus purpuratus) and smaller ochre sea stars (Pisaster ochraceus) as well as mussels, clams, smaller crustaceans, and dead or dying organic matter of any kind.
It can grow up to 30 inches in length, though 12 to 16 inches is much more common. Older males can weigh as much as 25 pounds. There are strict regulations placed on commercial and private fishermen, as this animal takes 5 to 10 years to reach sexual maturity—at which time it reaches only a mere 2 to 4 inches at best.
These lobsters are an integral part of the kelp forest food chain, keeping the urchin populations in check, thus helping kelp grow. They also serve as food to many animals, including marine mammals in the area as well as California’s large resident sheepshead wrasse (Semicossyphus pulcher). Though there are mixed reports of their lifespan, most seem to concede they are capable of living up to 50 years, during which they never stop growing completely.
As noted, chilled water is a necessity for these temperate animals, as they inhabit water in the mid-50s to occasionally the low 70s in extreme weather cells. I prefer to pick a number and keep it as stable as possible; Panulirus under my care are usually kept from 60° to 64°. You are more likely to see live specimens in the fresh-seafood section in your food market than an aquarium store, which is likely for the best, as this is the main species of this genus too often sold to reef/tropical aquarists.
Choosing a Tank :
Now here comes the fun part. Once you’ve decided that spiny lobsters are just so neat that you can’t live without them, it’s time to design an appropriate setup.
These animals need quite large tanks, and surface area is of optimal importance. Generally speaking, an ideal setup would have the width of the tank being at least 1½ times or, even better, twice the length of the animal. The length of the tank should also be at least 2½ times the length of the specimen.
Unlike many of the other animals we care for where surface area is a must, the height of the aquarium can be factored into usable area. Despite being clumsy, Panulirus are adept at climbing rocks, so sturdy overhangs can be used to create a stunning display. Total water volume for a fully grown lone specimen should be a minimum of 75 gallons, with 100 and 120 gallons being better choices. Again, due to the behavior, these do not have to be standard aquariums. Taller cylindrical aquariums that can be viewed in 360° with hiding/climbing centerpieces can really put the specimen in the spotlight so to speak.
As I mentioned earlier, the waste produced by a lobster can rival that of larger, predatory fish. While lobsters generally are a hardy lot, they are still invertebrates and water conditions need to be kept pristine at all times. The water volume should turn over 10 times per hour at minimum, with more turnover being preferable. An oversized and efficient protein skimmer is also a must in the lobster system. I would also consider employing the use of a macroalgae refugium for nutrient export.
In a dedicated species-only tank, there should be no need for high-intensity lighting. Nearly anything will do. Normal-output T-5 fluorescents are more than sufficient, but if you want to bring out the colors in your specimen, very-high-output T-5 fluorescents or LEDs (due to their adjustability and longevity) would be my aesthetic choice. Since lobsters are nocturnal, I would use a higher Kelvin rating (14,000k to 20,000k) to make the specimen comfortable and possibly encourage daytime activity. Red lights and moonlights are other viable options for viewing these creatures of the night. Moonlights are often included as options in many of the newer eco-friendly LED units as well.
Temperature Controller :
Depending on the needs of the individual specimen you keep, and the ambient temperature where the system is being held, heaters and/or chillers may be necessary to keep the water at the desired temperature. As with any aquarium specimen, the proper temperature for the animal should be targeted and held stable to the best of the owner’s ability.
Live Rock, Aquarium Décor, and Substrate :
As beautiful and majestic as these creatures may appear on the outside, inside lies a clumsy and destructive (whether it be on purpose or not) animal. Lobsters also need a lot of area to roam, so décor and live rock should be kept to a minimum.
Caves, overhangs, and similar types of structures should be stabilized with some type of media, such as a PVC frame or epoxy. Any loose items or structures could be easily toppled, and you could possibly end up with a crushed lobster. Lobsters that have just molted are particularly sensitive and vulnerable, and sharp, protruding objects should be avoided at all costs.
For aesthetic reasons, I would design any potential hiding areas, caves, and overhangs to be viewable even when the animal thinks it is out of sight. With a design like this, you will be able to view the animal even when it is attempting to be reclusive. The goal is to allow the animal to feel secure but still be able to enjoy it.
As for substrate, many spiny lobsters will often burrow to take refuge rather than go to the nearest rocky cave or overhang. To allow the lobster to perform this natural behavior, the substrate will need to be quite deep, around 6 inches. Lobsters also prefer coarse media and not oolitic sand, which has become so useful and popular in reef aquaria. With the coarse media and the lobsters’ burrowing capabilities, a true deep sand bed will become difficult to maintain in the display. I recommend weekly cleaning and vacuuming of the substrate to deter detritus accumulation. Should you wish to employ a deep sand bed, I suggest doing so in a dedicated refugium. On the same note, since décor must also be kept at a minimum, you can also place any extra live rock in the refugium to serve as a breeding ground for beneficial microfauna and nitrifying bacteria.
System Maintenance :
As with any aquarium, regular maintenance of a lobster system is key in keeping things stable and running smoothly. The tank’s parameters should be kept close to seawater levels. Weekly (or even more frequent) testing of the water parameters is mandatory. As I’m sure you know, ammonia and nitrite should always be at zero. Since a lobster is an invertebrate, you should attempt to keep nitrate as close to zero as possible, though a level of 10 ppm is acceptable.
The pH should be kept stable between 8.2 and 8.4. You can make this easier by maintaining high calcium levels (300 ppm to 450 ppm) and proper alkalinity levels between 8 and 12 dKH. In conjunction with the filtration system mentioned above, weekly water changes should be performed and detritus should be siphoned/vacuumed from the décor, rockwork, and substrate. Salinity should be maintained between 1.024 and 1.025.
General Lobster Care and Feeding :
Aside from the standard time and effort involved in keeping a marine aquarium, here are some special notes as far as lobster care goes.
As with all crustaceans, lobsters go through the process of molting, shedding their exoskeleton in order to grow. During and after this process, the lobster is very vulnerable to predation because it loses much of its protection in the molting process, The new exoskeleton is soft and requires time to harden. Lobsters are more likely to be eaten or picked on in the wild in this state and will remain rather reclusive for several days following the event. Likewise, if you’re keeping multiple lobsters or other crustaceans in the tank with the lobster, they may attempt to attack a freshly molted specimen.
I do not recommend removing the newly molted animal, as the process is stressful enough. Instead, utilize a piece of egg crate, starboard, or acrylic as an in-tank divider to protect the animal until it can defend itself again. The process of molting, which is often taken for granted by aquarists, is quite stressful on the animal. Honestly, it’s amazing they even make it from a planktonic pelagic stage to their more familiar form.
As far as feeding, these animals have a varied diet that you should attempt to duplicate as best as possible. Plan to keep at least five to six different foods on hand at all times and alternate between them. Utilize meat of marine origin, including (but not limited to) fresh market fish, scallops, clams, oysters, shrimp, krill, and squid. Some vegetable matter is necessary, such as spirulina, nori (dried seaweed), fresh algae(s), and even dry fare such as sinking wafers or pellets.
For enrichment, both nutritionally and mentally, offer your specimen some of its invertebrate food (such as bivalves and echinoderms) with the shell still intact. In fact, I have seen nutritionists in public aquaria routinely offer panulirids live sea urchins (after proper quarantine).
Occasionally soaking the foods in calcium or a beta-glucan supplement isn’t a bad idea. After molting, do not immediately remove the abandoned exoskeleton, as the specimen may attempt to consume it to some degree. Consuming their old home may be a way for them to regain lost calcium and various nutrients lost during the process.
As mentioned many times previously, the list of tankmates these lobsters can be kept with is short, though with a large-enough tank and hiding places, multiple specimens of the same species can coexist. With regard to other invertebrates, I have seen some hardy sessile invertebrates utilized in lobster tanks to add more appeal. Temperate and tropical corallimorphs, such as Corynactis californica(temperate), Discosoma spp., and Actinodiscus spp., can be potentially good choices.
As far as fish go, larger, slower-moving fish that won’t attack the lobster and vice-versa are at times utilized, though not without risk. For example, I have seen P. interruptus often housed with larger, local-to-its-area, gladiform fish such as Gadus macrocephalus. Both largely ignore the other.
Choose Wisely :
Hopefully this article has shown you that spiny lobsters are not to be casually included in community tanks or purchased on impulse when smaller and less destructive.
It will obviously take quite dedicated aquarists to set up such an elaborate display for a single specimen, especially with such a myriad of choices in the marine aquarium trade. I think, however, that we are starting to see a trend away from the mainstream, where aquarists are more inclined to adore oddball creatures and set up biotope displays, which I think is a positive. It gives the hobby more inclusion, expanding options to new or bored aquarists. To each his own; maybe a spiny lobster just happens to fit your persona. Whatever you choose to do, be responsible and care for your animals to the best of your ability. Good luck to you, and possibly your future lobster.
Spiny lobster migration - La migration des langoustes