Nature Blog Network

Saturday, September 29, 2007

'Monster' Lobster Caught by UK Fishermen and the Evolution of Their Tastiness

A giant pink spiny lobster has been found off the Cornish coast.

The 59.5cm (23in) long crustacean, nicknamed Poseidon, is five times larger than normal spiny lobsters and needs two people to pick him up safely.

Fishermen caught the lobster about 200 miles (321km) from Newlyn, along with two smaller spiny lobsters that were later sold at a fish market.

The Blue Reef Aquarium in Newquay is trying to establish if the "monster" is a record-breaking size.

The largest pink spiny lobster reported to have been found in the UK measured 70cm.

David Waines, of the Blue Reef Aquarium where the lobster is now housed, said: "Everyone here believes this is the largest specimen we've ever seen. He's a real monster.

"British records for this particular species are rare and we're still trying to establish whether Poseidon is a record-breaker."

The pink spiny lobster is closely related to the common crawfish[sic] but is usually found off the west coast of Africa and in the Mediterranean.
Now I wonder how closely related crays* are to lobsters. Fossil evidence suggests lobsters are derived from crays. For instance,
"The diversity and distribution of North American Triassic terrestrial burrowing and aquatic freshwater crayfish[sic] fossils demonstrates that their evolution began earlier and may reciprocate our views of the lobster-crayfish[sic] relationship. Crayfish[sic] fossils and the burrows attributed to their activity in the Upper Triassic Chinle Formation date to about 225 million years in age during the presence of the Pangean supercontinent.[...]The diversity, paleogeographic distribution, and ecological specialization of the Triassic crayfish[sic] implies that the group evolved possibly as early as or earlier than the Permian (286 million years ago). The crayfish[sic] body and trace fossil evidence may suggest that lobsters, thought to have evolved early in the Triassic (245 million years ago), evolved from aquatic freshwater crayfish[sic] that inhabited coastal streams, rivers, and lakes. The majority of lobster body fossils occur in the Jurassic and Cretaceous with only a hand full from the Triassic (e.g., Glaessner, 1969)"-Hasiotis 1993
So lobsters are derived from crays. This is probably not news to people who eat both. The nutritional facts speak to their shared common ancestry.

Nutritional analysis for crays from the Louisiana Crawfish[sic] Promotion & Research Board
Nutritional data for Crustacean, lobster, northern, raw.

It would appear that over the course of evolution, lobster meat gained 7 calories and 2g protein. The increase of sodium in lobsters of 203mg is striking and reflects their marine lifestyle. But how do we know lobsters are derived from crays and not merely intelligently designed? Clearly, anyone should be able to detect the sublime tastiness of the cray and lobster. It would almost appear that an intelligent designer specially created these delectable decapods for our own blissful satisfaction. Can tastiness really evolve? Crays are already very tasty crustaceans, so perhaps lobsters already carry the tasty gene and subsequent modifications on this gene or genes over evolutionary time increased their tastiness due to random genetic drift (expressed especially in the tail region). What amino acid contribute to their tastiness? Their protein quality index is identical to lobster, at over 100% for 9 essential amino acids: Tryptophan, Threonine, Isoleucine, Lysine, Methionine + Cysteine, Phenylalanine + Tyrosine, and Valine. Their amino acid content is summarized below.

Amino acid content form

Nothing really jumps out. Lobsters more protein and each amino acid content is higher than in cray by roughly the same proportion. Perhaps its in the mineral content? I already mentioned that lobsters have more sodium being a marine species. The iron to calcium ratio for lobster 0.25, while it is 2 for crays. Magnesium and phosphorus are equivalent. The only mineral crays have in more abundance is Iron.

It is perplexing, the similarities in their dietary components. Where does this tastiness come from? If crays and lobsters are sister taxa and their pre-harvest habitat results in similar nutritional data, then we are left with their post-harvet habitat to understand the evolution of their tastiness. Lobster tends to be sautéed in copious amounts of garlic, salted butter, and lemon pepper. Crays tend to be thrown into a potpourri of other quite tasty ingredients called a "jambalaya". The butter component adds a level of richness not observed in crays. Crays tend to be associated with tangy and spicy environments.

Based upon these observations, I hypothesize that tastiness is post-harvest environmentally driven. My analysis of nutritional content data support the fossil and morphological data and conclude with certainty that lobsters are derived from crays.
*In order to stabilize nomenclature and reduce parapolyphyletic entropy in the universe, I will not refer to "crawfish" or "crayfish". There is overwhelming evidence that crays, members of the phylum Arthropoda, are not derived from or closely related to fish (phylum Chordata) in way, morphologically or genetically.


  1. In order to stabilize nomenclature and reduce paraphyletic entropy in the universe...

    Especially when polyphyletic nomenclature is going to bite you in the ass :-P. To whit: freshwater crays and marine lobsters are members of the clade Astacura. The giant crayfish in the news is a member of the unrelated clade Achelata (or Palinura). Are lobsters descended from crays? Depends on which crays you're talking about.

  2. Thats what I get for writing at 1am with a tall glass of bourbon (after a dinner beer). Yes it would ;jnbe polyphyletic nomenclature since I arguing the 2 groups do not share a common ancestor.

    Hmm, confused a bit by your comment. The giant critter in the news and in the first part of this post is a spiny lobster NOT a cray.

    I tried to look for a cray/lobster molecular phylogeny to see if there were several independent events of going from freshwater to marine and whether there were hints of speciation back to freshwater. I'll have to look into when I have more time and revisit the question.

  3. Oops, I see the confusion - in New Zealand, the name 'crayfish' is used for your 'spiny lobster'. I guess I just saw the picture, thought 'crayfish' and filled in the blanks accordingly.

  4. If you were calling them crawdads instead, you wouldn't be having this confusion.

  5. Monster lobster = mobster.

    Or does that have a loaded meaning in the USA?

  6. Wait, I thought lobsters were related to otters. Or is that just "furry old lobster?" Like the ones in this song.


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