Wars: A Tale of Horseshoe Crabs, Ecology, and Human Health—2nd
Edition. By William Sargent. Brandeis
University Press. $24.95.
Superficially crablike but much more closely related to spiders and
scorpions, horseshoe crabs are nature’s blue bloods – literally. Their
copper-based blood is blue and extremely rare: there are other creatures with
non-red blood, such as some green-blooded skinks, but red is by far the
dominant blood color, and blue is precious. Extremely precious, as William
Sargent explains in Crab Wars.
This 2021 update of a book originally published in 2002 has lost none of
its relevance and has actually gained some in light of the COVID-19 pandemic.
In it, Sargent looks at the many strangenesses of the horseshoe crab, which has
lived largely unchanged for some 300 million years, and of how one particular
strangeness is of crucial importance to modern medicine, including attempts to
protect the world against the virus that causes COVID-19 and against whatever
viruses are yet to come. This is Limulus
amoebocyte lysate (simply called “lysate” for ease of reference), with which
horseshoe crabs shut down wound-invading bacteria in an elegant use of their
clotting system to fight infection.
What matters directly to humans who are not intrigued by horseshoe crabs
per se is that lysate has been found
to make possible the most-reliable test for so-called gram-negative bacteria – highly
dangerous organisms that are responsible for everything from meningitis to
typhoid to Legionnaire's Disease. It is hard to overestimate just how important
this makes lysate and, by extension, the horseshoe crab: every drug certified by the Food and Drug Administration must be
tested using a stabilized version of the crab’s lysate.
This of course means big money, big pharma, and big government, with
Sargent wryly noting that “what makes for good politics does not always make for
good medicine.” Indeed, some portions of Crab
Wars discuss situations that are good in neither context, such as the
attempt in 1976 to develop a swine-flu vaccine – which resulted in 52 deaths,
$1.7 billion in lawsuits, and “modern medicine’s most flagrant miscalculation.”
That debacle is what led to widespread use of the lysate test, which “was
faster, easier to use, and several times more sensitive than the rabbit test”
that had previously been the standard.
Enter the usual suspects of greed, ecology and human health (only
“greed” does not appear in the book’s subtitle, but it might as well be there).
Sargent spins out his story beyond science and medicine into areas both wider
and narrower, the latter giving a personal spin to the whole horseshoe-crab
saga (“I was facing the summer penniless, unemployed, and stuck in the city” –
that sort of thing). The zipping back and forth between larger and smaller
issues can be disconcerting, although the desire to personalize the science
this way is admirable. It is not the main story, however. That one involves the
use of horseshoe crabs as bait, the ways in which the crabs fit into the
overall ecosystem of which they are a part (everything
fits into the ecosystem of which it is a part), and arching above all, the
increasing importance of lysate for preserving human health – that is, the use
of horseshoe crabs as a weapon against humanity’s eternal microscopic enemies.
The book is in four sections called “Early Lessons,”
“Commercialization,” “Environmental Conflicts,” and “Crabs and COVID.” Much of
the material in the third portion of the book is predictable, involving
wildlife protection, multinational corporations, exploitation (or simply “use,”
a less-loaded word) of a finite resource, and peculiar details of the U.S.
political system, such as arguments about how many horseshoe crabs from which
source could be transferred for what purpose to where else. The fourth section,
though, becomes truly intriguing, and not just because it brings matters more
or less up to date. This section starts with “the five major producers” of
lysate “bleeding several hundred thousand crabs a year and making tens of
millions of dollars.” It then moves into an area that, at least in retrospect,
seems obvious: why not protect the crabs, the ecology that depends on them, and
the human race, by creating a synthetic substitute for lysate? It turns out
that there is one, thanks to the diligent research in Singapore of Dr. Ling Jaek
Ding, who was able to produce the alternative by some clever and lengthy work
involving insects: “Insects and horseshoe crabs share their lineage through
arthropods, which is much closer than the lineage they share with yeasts and
Dr. Ling’s alternative, though, has yet to be widely accepted, for
reasons relating to politics, government ineptness, corporations’ reluctance to
change, and the exigencies of the COVID-19 pandemic. It is because of the
pandemic that the FDA has been slow to move on approving an alternative to use
of lysate – although Sargent predicts that “within a year or two when the
immediate crisis of the COVID pandemic passes, the FDA will approve” the
alternative to use of horseshoe-crab blood for crucial medical testing. He
suggests that even as that occurs, new government regulations should protect
horseshoe crabs against being used as bait, modeling human handling of the
crabs on our current regulation of the lobster industry. And he concludes with
a once-over-lightly about COVID-19 vaccines and the continuing need for lysate
Crab Wars is a short book – 160 pages – and refreshingly non-academic despite its publication by an academic press. It is intermittently fascinating but somehow, despite its brevity, is rather diffuse. Sargent seems hesitant to get too deeply into any of the topics he broaches, from horseshoe-crab anatomy to his own scientific interests to the corporate and governmental issues raised by horseshoe-crab management and wildlife management in general. All the topics are there, but in his largely successful determination to present a science/medicine book with a breezy style, Sargent is less than wholly successful in arguing for the seriousness of his purpose. That seriousness is in the book, as when Sargent writes that “if we were to lose all the lobsters, striped bass, or shrimp on the East Coast, it would be an environmental tragedy. But if the East Coast were to lose all its horseshoe crabs, it would be a major medical disaster.” But even so dire a statement as this is basically made in passing, on the way from one part of the story to the next, and therefore does not make the reader really sit up and take notice. In his desire to avoid being overly academic or overly alarmist, Sargent has produced a book that is closer to being a meandering (if brief) memoir than one with an intimate focus on an amazing creature whose fate is intimately intertwined with our own.