KWAJALEIN MOLLUSCA
Jeanette and Scott Johnson
uwkwaj@yahoo.com
6-Aug-2020
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This list contains information about the mollusks found at Kwajalein Atoll, Marshall Islands.  Tabs at the bottom of the page bring up the listing itself, crude drawings of Kwajalein Atoll habitats and a list of references. In addition to the family, genus, species, and author (where known) of each species, the list contains columns for:
REFERENCE:  The book or paper we used to identify the species.  References are in the form X:Y, where X is the reference number listed in the  bibliography and Y is the page or  plate number.  For example, 170:215 means . This shell was identified using reference 170 (E.A. Kay's Hawaiian Marine Shells), page 215.
LOC:  The locations where the species have  been found at Kwajalein (see the location key below).   Due to weather conditions at Kwajalein, we've put by  far the most effort into collecting on the oceanside of  the west reef (W), lagoon pinnacles (P), and lagoonside of  the east reef (e).  In particular, the lagoon bottom (B) has  received little attention, as have oceanside east reef (E)  and shipwrecks (S).  Also, we've only sporadically collected  lagoonside west reef (w) and intertidally.  We've made some attempt  to list the location where we've found the species to be most common first.
DEPTH and HABITAT:  The general habitat of the species (or, at least, where specimens have been found at Kwajalein-see the habitat key below).  Some habitats include others.  For example, C (in cave) includes CN (in cave at night); CN is used when specimens are found in caves only at night.  Species listed as CN are probably still in those caves during the day-they're just hidden well enough then to not be found by divers.  Some of these habitats are specific to one or very few species.
SIZE:  A maximum size or size range in millimeters.  Maximum sizes for many popular species (e.g., most cones and cowries) are from a "Kwaj Shell Record" list maintained at Kwajalein since the early 1970s, and are therefore more comprehensive than sizes for less well known species.
RAR:  A relative rarity value (see rarity key below).  Rarity estimates are subjective and assume that you are looking in the correct habitat (e.g., Monetaria moneta is a 1 in the rocky intertidal, but it's not if you're looking in the sand at 100 feet).  Rarities listed are based on our own experience plus input from several other knowledgeable Kwaj shellers.  Many rarities, particularly those of obscure families, micromollusks, and species inhabiting locations we have poorly searched, will need to be revised as we get more information. Also, some species come and go. For example, Palmadusta asellus is very rare here, with fewer than one found per year. But one year, more than a dozen specimens, all empty, were found. 
Where possible, unidentified species were determined to family or genus based on similarities to known species.  Generic ids are therefore often tentative.
The list is unfinished.  We continue to add species; identify unknowns; and update location, habitat, size, and rarity information. Name changes based largely on molecular (DNA) studies cause the names to go out of date rather quickly.
KEY CODES
LOCATION KEY
B = Lagoon bottom (deeper than 100 feet)
E = Oceanside east reef
e = Lagoonside east reef
H = Lagoon slope Halimeda patch
I = Interisland intertidal reef
K = Kwajalein Atoll (exact location unknown)
L = Lagoon
N = Ninni Pond (salt water "lake" at Ninni Is.)
P = Lagoon pinnacles
Q = Oceanside man-made reef quarry
R = Oceanside intertidal reef
S = Shipwreck
W = Oceanside west reef
w = Lagoonside west reef
RARITY KEY
1 = Can always be found in quantity (in the correct habitat)
2 = Can almost always be found if you're looking for it
3 = Is often found but not every time you look
4 = Not especially easy to find even when you know the habitat
5 = Seldom found even with diligent searching
6 = Very rarely found (fewer than three specimens found at Kwaj each year, or for some other reason known to be extremely hard to find)
7 = Only one specimen known from Kwaj
HABITAT KEY
A = Associated with macro algae
AN = Associated with anemone
AT = Associated with Antipatharian
B = Beach
BO = Bores into reef
BR = On bryozoan
BU = On buoy or line
C = Cave (large cavern or small hole)
CN = In cave at night
CR = Cemented to reef
CS = Silty sand deep in cave
D = Found dead (habitat unknown)
E = Exposed in rocky areas
EG = Feeding on egg mass
EN = Exposed at night
F = On Fungia (razor coral)
FC = On  Millepora (fire coral)
FD = Growth under floating dock
FS = In or on flake sand
G = On gorgonian
GR = In grunge (sandy rubble bagged at depth and sorted on the surface)
HA = On Halimeda algae
HE = On Heliopora (blue coral)
HO = On holothurian (sea cucumber)
HY = On hydroid
LC = On live stony coral
M = Fine silty muck on shipwreck
OS = On the surface of sand
PA = Parasitic on fish at night
PP = Pier pilings
PU = On pencil urchin spine
R = Among or under coral rubble
RP = In reef pocket
RS = In or on rubbly sand
S = Buried in open sand
SC = On soft coral
SF = On starfish
SG = On sponge colony
SH = On mollusk shell
SL = In thin layer of sand over rock
SP = In sand pocket
SR = In sand under rock
ST = On Strombus taurus shell
SU = On sea urchin
SW = On shipwreck
SY = On Stylaster (pink coral)
TY = On Tydemania algae
U = Under dead coral rock
UP = Under Porites coral
X = On Xenia 
Z = On Palythoa or Zoanthus