Why is a lobster's blood blue, and which claw makes it left-handed? These lobster trivia questions and answers fill five rounds, the last of them on crabs.
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Five rounds, from the berried female to the lobster smack
Names and relatives tells the American lobster from the European by the spines on its claws. Claws, shell and senses finds the telson and the bladders beside the head. Molts, eggs and food follows a metanauplius down to the sea floor. Traps, boats and history reads a V-notch and a ghost panel. Crabs runs from the pea crab to Karkinos.
Crustaceans trivia questions and answers for a shore night
A tap on any of the four choices settles it: right or wrong, a line of reason, and the article it came from. Sets hold ten. In Scored round nothing is marked until twenty answers are in.
Questions and answers
Why is lobster blood blue?
Lobster blood carries hemocyanin, which contains copper, and that makes it blue. Vertebrates have red blood from iron-rich hemoglobin.
How long do lobsters live?
In the wild a lobster may reach 45 to 50 years, by estimate. Its age is hard to tell, so it is usually worked out from its size and other measures.
Are there crab trivia questions here too?
Yes. The round named Crabs asks about true crabs, hermit crabs, king crabs and porcelain crabs, and about the horseshoe crab, which belongs with the spiders and scorpions.
How were the answers checked?
Each was read on October 3, 2026 in the English Wikipedia articles Lobster, American lobster or Crab; every question links its own. Cooking, killing methods, legal sizes, record weights and diseases are left out, and so is one point the two lobster articles disagree on.
The American lobster is the heaviest living species of which large group of animals?Answer: Arthropods. Source: Wikipedia: American lobster
The American lobster ranges from Labrador south to which cape?Answer: Cape Hatteras, North Carolina. Source: Wikipedia: American lobster
The first description of the American lobster named which state's coast as the place it came from?Answer: New Jersey. Source: Wikipedia: American lobster
The fossil record of clawed lobsters reaches back at least to which period?Answer: The Cretaceous. Source: Wikipedia: Lobster
In 2013 an American lobster turned up at the Farallon Islands. Off which state's coast are they?Answer: California. Source: Wikipedia: American lobster
Lobsters belong to the order of decapods. What does that name mean?Answer: Ten-footed. Source: Wikipedia: Lobster
The spines on an American lobster's claws are red. What color are they on a European lobster?Answer: White or white-tipped. Source: Wikipedia: American lobster
What is the scientific name of the American lobster?Answer: Homarus americanus. Source: Wikipedia: American lobster
Which family holds the clawed lobsters?Answer: Nephropidae. Source: Wikipedia: Lobster
Which freshwater animals are among the closest living relatives of clawed lobsters?Answer: Crayfish. Source: Wikipedia: Lobster
Which lobster is the closest relative of the American lobster?Answer: The European lobster. Source: Wikipedia: American lobster
Which of these is another name for the American lobster?Answer: Maine lobster. Source: Wikipedia: American lobster
Which small lobster is also known as langoustine or true scampi?Answer: The Norway lobster. Source: Wikipedia: Lobster
Who first described the American lobster for science, in 1817?Answer: Thomas Say. Source: Wikipedia: American lobster
Claws, shell and senses 19
A lobster's abdomen carries pleopods, used for swimming. What is their common name?Answer: Swimmerets. Source: Wikipedia: Lobster
A lobster's body has two main parts: the abdomen and which other?Answer: The cephalothorax. Source: Wikipedia: Lobster
A lobster's tail fan is made of the uropods and which other part?Answer: The telson. Source: Wikipedia: Lobster
Besides sensing smells, what can a lobster's antennules judge?Answer: Water speed. Source: Wikipedia: American lobster
How does a lobster swim when it flees?Answer: Backward, by curling and uncurling its abdomen. Source: Wikipedia: Lobster
How does the lobster eye differ from most complex eyes?Answer: It has a reflective structure where most have lenses. Source: Wikipedia: Lobster
How many of a lobster's five pairs of legs carry claws?Answer: Three. Source: Wikipedia: Lobster
How many walking legs does a lobster have?Answer: Eight. Source: Wikipedia: Lobster
Living in murky water on the sea bottom, lobsters mostly use what as sensors?Answer: Their antennae. Source: Wikipedia: Lobster
What color is a lobster's blood?Answer: Blue. Source: Wikipedia: Lobster
What decides whether a lobster is left-handed or right-handed?Answer: Which side its crusher claw is on. Source: Wikipedia: American lobster
What is a lobster's fast backward escape called?Answer: The caridoid escape reaction. Source: Wikipedia: Lobster
What is the larger claw of an American lobster, with its rounded nodules, called?Answer: The crusher. Source: Wikipedia: American lobster
What is the normal color of a live American lobster?Answer: Bluish green to brown. Source: Wikipedia: American lobster
Where are a lobster's two urinary bladders?Answer: On either side of the head. Source: Wikipedia: American lobster
Which green organ does the work of a lobster's liver and pancreas?Answer: The hepatopancreas. Source: Wikipedia: Lobster
Which metal is in hemocyanin, the pigment of lobster blood?Answer: Copper. Source: Wikipedia: Lobster
Which pigment do all lobsters except albinos carry?Answer: Astaxanthin. Source: Wikipedia: American lobster
Why does a lobster have a pair of smell organs?Answer: To tell which direction a smell comes from. Source: Wikipedia: American lobster
Molts, eggs and food 18
A female lobster carrying eggs is said to be in what?Answer: In berry. Source: Wikipedia: American lobster
A young American lobster molts about ten times a year. How often does an older one molt?Answer: Once every few years. Source: Wikipedia: American lobster
About how many American lobster larvae are thought to survive to the juvenile stage?Answer: 1 in 1,000. Source: Wikipedia: American lobster
After its larval stages, where does a young American lobster settle?Answer: On the ocean floor. Source: Wikipedia: American lobster
As which kind of larva does an American lobster hatch?Answer: A metanauplius. Source: Wikipedia: American lobster
For about how long does a female American lobster carry her eggs?Answer: 10 to 11 months. Source: Wikipedia: American lobster
If threatened, what will an adult American lobster generally choose to do unless it has lost its claws?Answer: Fight. Source: Wikipedia: American lobster
In which kind of water does the American lobster thrive?Answer: Cold, shallow and rocky. Source: Wikipedia: American lobster
Lobsters in Maine have been shown to get a large share of their calories from which fish, used as trap bait?Answer: Herring. Source: Wikipedia: American lobster
Of the lobsters that enter a trap to feed, about what share is caught?Answer: 6 percent. Source: Wikipedia: American lobster
Off New England, in which months does the American lobster typically lay its eggs?Answer: July or August. Source: Wikipedia: American lobster
Tiny animals of the genus Symbion live only where?Answer: On the gills and mouthparts of lobsters. Source: Wikipedia: Lobster
Up to about what age are lobsters estimated to live in the wild?Answer: 45 to 50 years. Source: Wikipedia: Lobster
What do lobsters do with their shed skin after molting?Answer: Eat it. Source: Wikipedia: Lobster
Where does a female American lobster carry her eggs until they hatch?Answer: On her swimmerets. Source: Wikipedia: American lobster
Which enzyme, active in adult lobsters, has been suggested as a reason for their long lives?Answer: Telomerase. Source: Wikipedia: Lobster
Which prey dominates the natural diet of the American lobster?Answer: Mollusks such as mussels, clams and snails. Source: Wikipedia: American lobster
Why must a lobster shed its shell?Answer: To grow. Source: Wikipedia: Lobster
Traps, boats and history 13
A lobster trap lets a lobster walk in. Which move does it make hard for a large one?Answer: Turning around to leave. Source: Wikipedia: American lobster
A lost trap's ghost panel opens in time and lets the catch out. What holds it shut until then?Answer: Degradable metal clips. Source: Wikipedia: American lobster
A mosaic showing a spiny lobster was found in the ruins of which Roman city?Answer: Pompeii. Source: Wikipedia: Lobster
Before lobster was prized, fishermen often put it to which use?Answer: Fish bait. Source: Wikipedia: Lobster
By which year had Maine's lobster canning industry disappeared?Answer: 1895. Source: Wikipedia: Lobster
In which Maine town did the first lobster cannery in the United States open in the 1840s?Answer: Eastport. Source: Wikipedia: Lobster
Lobster shells thrown out by canneries were once spread on fields as what?Answer: Fertilizer. Source: Wikipedia: Lobster
Lobster shells were once used to make a dye of which color?Answer: Light pink. Source: Wikipedia: Lobster
What are lobster traps sometimes called?Answer: Pots. Source: Wikipedia: American lobster
What does a lobster fisher's gauge measure?Answer: From the eye socket to the end of the carapace. Source: Wikipedia: American lobster
What marks the place of a lobster trap from the surface?Answer: A color-coded buoy. Source: Wikipedia: Lobster
Which boat, with open holding tanks on deck, let lobster fisheries flourish?Answer: The lobster smack. Source: Wikipedia: Lobster
Which mark do American lobstermen cut in the tail of an egg-bearing female before she goes back into the sea?Answer: A V-notch. Source: Wikipedia: Lobster
Crabs 19
Among true crabs, which often have the larger claws?Answer: Males. Source: Wikipedia: Crab
Crabs are described as polyphyletic. What does that mean?Answer: They have multiple evolutionary origins. Source: Wikipedia: Crab
The hairy stone crab is a slow-moving crab of which shore?Answer: The Australian shore. Source: Wikipedia: Crab
Horseshoe crabs are known from rocks of which period, about 445 million years ago?Answer: The late Ordovician. Source: Wikipedia: Crab
How do porcelain crabs feed?Answer: By filtering plankton from seawater. Source: Wikipedia: Crab
In Greek myth, the crab Karkinos came to the aid of which monster as it fought Heracles?Answer: The Lernaean Hydra. Source: Wikipedia: Crab
In one of the Just So Stories of Rudyard Kipling, what does a gigantic crab make the sea do?Answer: Go up and down like the tides. Source: Wikipedia: Crab
King crabs resemble true crabs. Which animals are they more closely related to?Answer: Hermit crabs. Source: Wikipedia: Crab
The tiny oyster crab lives inside an oyster's shell and eats its host's food. What kind of parasite is it?Answer: A kleptoparasite. Source: Wikipedia: Crab
What do porcelain crabs often do to escape a predator?Answer: Shed a limb. Source: Wikipedia: Crab
What is carcinization?Answer: The evolution of a crab-like body form. Source: Wikipedia: Crab
What is the scientific name for the true crabs?Answer: Brachyura. Source: Wikipedia: Crab
Where do king crabs mainly live?Answer: In cold deep water. Source: Wikipedia: Crab
Which constellation is named after the crab?Answer: Cancer. Source: Wikipedia: Crab
Which crab has the greatest leg span of any crab?Answer: The Japanese spider crab. Source: Wikipedia: Crab
Which crab is only a few millimeters wide?Answer: The pea crab. Source: Wikipedia: Crab
Which crab is the largest arthropod that lives on land?Answer: The coconut crab. Source: Wikipedia: Crab
Which German artist painted a meticulous study of a crab in 1495?Answer: Albrecht Dürer. Source: Wikipedia: Crab
Why do Christmas Island red crabs make a mass march to the sea each year?Answer: To lay their eggs. Source: Wikipedia: Crab
How this list was compiled
Written for this site; nothing was copied from another list. Questions and wrong choices are our own. Each explanation restates, in our own sentences, a fact from the English Wikipedia article named and linked beside the question (https://en.wikipedia.org, text under the Creative Commons Attribution-ShareAlike 4.0 license): Lobster, American lobster and Crab. On October 3, 2026 the passage that states each fact was read in its article before the question was kept. Left out on purpose: recipes, cooking and killing methods, welfare laws, legal sizes and fines, catch tonnages, record weights, market grades, diseases and mating. Whether wild lobsters eat one another is not asked, because the two lobster articles disagree. Levels are our estimate: easy is fair for any table, medium suits people who know the animal, hard will stump most tables. Unofficial, and not advice on keeping, feeding or approaching an animal. Licence: own work