not in Hawaii's
Spiders, so called because they have four pairs of legs, are small
marine arthropods of the class Pycnogonida. They are thought to
be related to spiders and horseshoe crabs. The Bishop Museum's list
of pycnogonids known in Hawaii is here
Sea Spider (unidentified)
Chuck Babbitt photographed this small animal
in 65 feet of water at a spot he calls Disneyland, straight out
from the new Disney resort at Ko Olina, West Oahu, and sent me the
photo to ID. It seems to be a pycnogonid, more commonly known as
a "sea spider." and can be identified as such by its four
pairs of long, slender legs (although a few pycnogonids have 5 or
6 pairs of legs). Small and well camouflaged, these tiny, slow-moving
predators are noticed only by the most sharp-eyed of divers. Most
species are probably less than 1/2 in long. According to the Bishop
Museum, there are about 15 known species of sea spiders in Hawaiian
waters, but I don't have a clue how to figure out which one this
is. I didn't even think to mention these obscure animals in my book
Hawaii's Sea Creatures. Thanks, Chuck, for bringing them
to my attention!
6, 2016 I received more photos from David Rolla of what might be
the same unidentified species. This individual was carrying a large
white egg mass under its abdomen. David wrote:
At the end of a dive today, I found a sea
spider ... The photo on your site is familiar to me...Chuck Babbitt
is a friend, and I was diving with him the day we found the one
in his photo. Coincidentally, he took us out on his boat today and
I found another one
not so tiny.
one appears to be very similar to the previous one except
larger. Id estimate the size at 1/2 across. It was actively
crawling along the mooring line at about 85 on the deep LCU
wreck on the west side of Oahu. It also appeared to have a solid
white body, but now as I take a close look at my photo and Chucks
photo, I believe it is carrying something
perhaps an egg mass,
or a big meal?
Im guessing we still dont know which of the 15 species
this could be
just thought you may be interested to see this
David Rolla's photos, Cory Pittman wrote that he had photos of several
other sea spiders found in algae washes done by him and Pauline
Fiene over the years. Cory writes:
There are actually quite a few species in
Hawaii (most small and cryptic). Like John, however, I have no idea
about identification. Several small ones are fairly common in my
algae washes and I have photos of three or four. My largest reaches
about 20 mm in leg-spread and is peculiar in that its body is transparent
and its digestive system is dark green. It's a Halimeda-dweller.
So, that might provide camouflage. But, I also wonder if it's retaining
chloroplasts--perhaps picked up secondarily from its prey since
they're all supposed to be predators.
first two shots are of small animals (around 4-5 mm in leg spread,
if I recall correctly--I didn't record it at the time). They were
both from an algae wash taken at Maliko Bay, Maui at 3-9 m on April
next two are of the large, Halimeda-dwelling species I mentioned.
first animal had a leg spread of about 16 mm. It was from pooled
algae washes taken by Pauline and me in a Halimeda kanaloana
bed at a depth of 6-14 m about 3.5 km north of Hekili Point, Maui
on October 11, 2003.
second animal had a leg spread of about 15 mm. It was from an algae
wash taken by Pauline (with me sorting) in a Halimeda kanaloana
bed at a depth of 8-11 m at Wahikuli, Maui on Nov. 6, 2010.