South Pender Island,
south end of island

C. nuttallii  [2]

C. gigantea  [4]
C. gigas  [4]

H. arctica  [4]

L. staminea  [2]

M. inquinata  [3]

M. arenaria  [2]

M. complex  [3]

N. obscurata  [3]

P. penita  [4]
P. richardsoni  [4]
P. turnerae  [4]
P. macrochisma  [4]

S. gigantea  [2]

T. capax  [2]

Z. pilsbryi  [2]


C. foliatum  [4]

C. sp.  [4]

D. aspera  [4]

L. scutulata  [2]

L. pelta  [3]

L. persona  [3]

M. pupillus  [4]

N. eschrichtii  [4]

N. lamellosa  [3]

N. ostrina  [4]

O. tenuisculpta  [4]



M. kennerleyi  [4]

M. lignosa  [3]
M. muscosa  [4]
M. sinuata  [4]
M. cf. spectabilis  [4]
M. swanii  [4]


Dorid sp. - white  [4]

Thetis Island -
  Pilkey Pt. at north end (n), south end (s)

C. nuttallii  [n3,s2]

C. gigas  [n2,s1]

C. californica [s3]

H. arctica  [n4,s4]

L. staminea  [n2,s2]

M. balthica  [s4]
M. inquinata  [n3,s2]
M. nasuta  [n4,s2]
M. secta  [s4]

M. arenaria  [n4,s3]

M. complex  [n2,s1]

N. obscurata  [n3,s1]

P. macrochisma  [n3,s3]

S. gigantea  [n2,s2]

S. sicarius  [s4]

T. capax  [n3,s2]
T. nuttallii  [s3]
V  philippinarum  [n2,s1]
Z. pilsbryi  [s4]


A. carinata  [s4]

B. attramentaria  [s1]

C. lingulata  [n4]

Lacuna sp.  [n4,s4]

L. scutulata  [n1,s1]

L. digitalis  [s4]

L. pelta  [n2,s3]

L. persona  [n3,s2]
L. scutum  [n4,s3]
M. pupillus  [n4,s4]

N. mendicus  [s4]

N. lewisii  [n4,s3]

N. lamellosa  [n4,s2]

N. ostrina  [s3]

O. tenuisculpta  [s4]


C. dentiens  [n4subtidal,s4]

L. mertensii  [n4,s4]
L. radians  [n4subtidal]

M. kennerleyi  [n4,s4]

M. lignosa  [n3,s2]
M. muscosa  [s4]
M. sinuata  [n4]

M. vespertina  [n3,s3]

T. lineata  [n2,s3]

T. undocaerulea  [n4,s4]


D. iris  [n4subtidal]

D. odonoghuei  [s4]

D. montereyensis  [s4]

H. japonica  [n4] (Cufra Inlet)
H. vesicula  [n4,s2]

H. crassicornis  [s4]

M. leonina  [s4]

Gabriola Island -
west side (w), reef (r)


C. nuttallii  [w2]

C. gigas  [w2,r4]

D. impolita  [r3]
E. navicula  [w4,r4]
G. californica  [w4]
G. septentrionalis  [r4]
H. arctica  [w4,r2]

K. suborbicularis  [r4]
L. staminea  [w2,r3]

M. inquinata  [w3,r4]
M. nasuta  [w3]

M. modiolus  [r4]
M. arenaria  [w3]

M. complex  [w1,r1]

N. obscurata  [w2]

P. penita  [w3,r3]
P. richardsoni  [w3]

P. macrochisma  [w4,r4]

S. gigantea  [w1,r2]

T. capax  [w3,r4]
T. nuttallii  [w4]
V. philippinarum  [w2]


A. carinata  [r4]
A. columbiana  [r4]

C. lingulata  [w3]

D. aspera  [r3]

L. vincta  [w3,r4]
L. dirum  [w4]
L. scutulata  [w1]

L. pelta  [w3,r3]
L. persona  [w3]
L. scutum  [w4,r4]
M. pupillus  [r4]

M. micans  [r4]

N. eschrichtii  [r3]
N. lewisii  [w3]

N. lamellosa  [w2,r4]
N. ostrina  [w3]

O. tenuisculpta  [r4]



C. dentiens  [r3]
K. tunicata  [r4]

L. mertensii  [w4,r4]
L. radians  [w4]

L. rugatus  [w4]
M. hindsii  [r4]
M. kennerleyi  [w4,r4]
M. lignosa  [w4,r4]

M. sinuata  [r4]
M. spectabilis  [w4]
M. swanii  [r4]
M. vespertina  [r4]

T. lineata  [w3,r3]


A. hudsoni  [w4]

A. nanaimoensis  [w4,r4]

C. luteomarginata  [r4]


D. odonoghuei  [r4]

H. crassicornis  [w4]

O. trilineata  [r4]

Southern Gulf Islands, BC

Site Description:       

The Southern Gulf Islands are in the Strait of Georgia just off the southeast coast of Vancouver Island.  They are directly adjacent to the San Juan Islands in Washington.   The islands have rocky outcroppings which  frequently consist of sandstone.  There are sand/mud stretches between the outcroppings in places and these often have erratic boulders.  Some areas have sand/gravel or sand/mud beaches.  Our data is collected from several islands, both intertidal and subtidal.  We list some representative sites from points across the islands, covering the various types of beaches typical here.  Gabriola Island is the northernmost island.  Thetis Island is an interior island, surrounded by others, and is located slightly north of center among this island group.  Pender is located at the southern end of the Gulf Islands.  We add a few notations in the general list for some species located immediately adjacent in the Nanaimo area.

Google Map

                Gabriola Island, west side                                               rock reef west of Gabriola Island, only exposed at low tide

             southeast end of Thetis Island, left - a mud/sand cove, right - stone outcroppings separated by muddy sand

                 Pilkey Point, north end of Thetis Island                             channel between North and South Pender Islands

Species List:

     Following is a list of mollusk species observed at this location by members and associates of the club.  This is by no means a complete list of the species which may occur at this site.  Revisions and additions to the data are made as we acquire new information.   When a site contains more than one very distinctive type of habitat or if multiple sites were included in a single location, then a species list for each is included.
    We indicate frequency of occurrence based on our observations.  This is an indicator of how likely it is that you may be able to find this species yourself and is not a formal population survey.  

     Frequency Code:  (Based on the assumption that you are looking in the appropriate location where the species
                                          likes to live - on rocks, in sand, etc.  Some populations fluctuate seasonally.  Ours are based
                                          on the spring/summer seasons.)
     [4] - Rare - very difficult to find, maybe only a couple found after repeated visits to the site
     [3] - Uncommon - difficult to find, may not see on every trip but dedicated searching may turn up a few
     [2] - Common - easy to find, should locate a number of them on any given day
     [1] - Abundant - very easy to find, large numbers should be seen on every trip

Due to the nature of the data, the general list will not be rated for frequency of occurrence as this may vary by actual location. The two specific survey sites listed consist of intertidal data unless noted and they are rated for frequency.

On Thetis Island, our north end data site is predominantly rocky.  Across the south end of Thetis is an extensive stretch of sand/mud habitat with a few rocky places.  Our south side data is an average of those beaches.

Intertidal - I
Subtidal - S                                                          

 All Island List

Bankia setacea  I,S
Chlamys hastata  S
Chlamys rubida  S
Ciliatocardium ciliatum  S
Clinocardium nuttallii  I,S
Crassadoma gigantea  S
Crassostrea gigas  I,S
Cryptomya californica  I
Diplodonta impolita  I
Entodesma navicula  S

Gari californica  S
Glycymeris septentrionalis  S
Hiatella arctica  I
Humilaria kennerleyi  S
Keenocardium blandum  S
Kellia suborbicularis  S
Leukoma staminea  I,S
Limatula attenuata  S
Lyonsia californica  S
Macoma balthica  I
Macoma inquinata  I
Macoma nasuta  I  
Macoma secta  I
Modiolus modiolus  S
Mya arenaria  I

Mya truncata  S
Mytilimeria nuttallii  S
Mytilus galloprovincialis  I,S
Mytilus complex  I,S
Mytilus trossulus  I,S
Netastoma rostratum  I
Nuttallia obscurata  I

Panopea generosa  S
Patinopecten caurinus  S
Penitella penita  I
Penitella richardsoni  I
Penitella turnerae  I
Pododesmus macrochisma  I,S
Rhamphidonta retifera  I (Nanaimo)
Saxidomus gigantea  I,S

Semele rubropicta  S
Simomactra falcata  I
Solen sicarius  S
Tresus capax  I,S
Tresus nuttallii  I,S
Venerupis philippinarum  I,S
Yoldia seminuda  S
Zirfaea pilsbryi  I,S
Aclis shepardiana (at Nanaimo)
Acmaea funiculata  S  
Acmaea mitra  I,S
Alia carinata  I
Amphissa columbiana  S

Batillaria attramentaria  I
Calliostoma annulatum  S
Calliostoma ligatum  S
Calliostoma variegatum  S
Calyptraea fastigiata  S
Ceratostoma foliatum  S
Cidarina cidaris  S
Crepidula sp.  I
Crepipatella lingulata  I
Cryptobranchia concentrica  S

Cryptonatica aleutica  S
Diodora aspera  I,S          
Epitonium indianorum  S   
Fusitriton oregonensis  S
Haliotis kamtschatkana  S
Lacuna vincta  I,S
Lirobuccinum dirum  I,S 
Littorina scutulata  I
Littorina sitkana  I               
Littorina subrotundata  I
Lottia digitalis  I

Lottia instabilis  S
Lottia limatula  I
Lottia pelta  I
Lottia persona  I
Lottia scutum  I,S
Margarites pupillus  I,S
Marsenina stearnsi  S
Melanella micans  I
Nassarius mendicus  I
Neostylidium eschrichtii  I
Neverita lewisii  I,S
Nucella canaliculata  S
Nucella lamellosa  I,S
Nucella ostrina  I
Paciocinebrina interfossa  S

Paciocinebrina lurida  S
"Odostomia" tenuisculpta  I
Petaloconchus compactus  S

Puncturella cucullata  S
Scabrotrophon maltzani  S
Trichotropis cancellata  S

Cryptochiton stelleri  I,S    
Cyanoplax dentiens  I,S
Katharina tunicata  I,S

Lepidozona cf. interstincta  S
Lepidozona mertensii  S

Lepidozona radians  I
Lepidozona cf. radians  S

Leptochiton cf. rugatus  I
Mopalia hindsii  S
Mopalia kennerleyi  I
Mopalia lignosa  I,S

Mopalia muscosa  I,S
Mopalia sinuata  I,S
Mopalia spectabilis  S

Mopalia swanii  I,S
Mopalia vespertina  I,S
Placiphorella rufa  S
Tonicella insignis  S
Tonicella lineata I,S
Tonicella undocaerulea  I
Tripoplax trifida  S

Acanthodoris atrogriseata  S
Acanthodoris hudsoni  S
Acanthodoris lutea  S
Acanthodoris nanaimoensis  S
Adalaria proxima  S
Aeolidia loui  I,S
Aldisa cooperi  S
Aldisa tara  S
Antiopella fusca  S
Armina californica  S
Berthella californica  S
Cadlina luteomarginata  S
Cadlina modesta  S
Clione limacina  I,S
Cliopsis krohni  S
Coryphella verrucosa  S
Dendronotus albus  S
Dendronotus iris  S
Dendronotus venustus  I,S
Diaulula odonoghuei  I,S
Dirona albolineata  I,S
Dirona pellucida  S
Doris montereyensis  I,S
Doris odhneri  S
Gastropteron pacificum  I,S
Geitodoris heathi  S
Haminoea japonica  I
Haminoea vesicula  I,S
Hermissenda crassicornis  I,S
Himatina trophina  S
Limacia cockerelli  S
Limacina helicina  S
Melibe leonina  I,S
"Montereina" lentiginosa  S
Onchidoris bilamellata  I,S
Onchidoris evincta  S
Orienthella trilineata  S
Peltodoris nobilis  I,S
Phyllaplysia taylori  I,S
Retusa obtusa  I
Rostanga pulchra  S

Tochuina gigantea  S
Triopha catalinae  S
Tritonia exsulans  S
Tritonia festiva  S
Ziminella japonica  S

Onchidella borealis  I

Doryteuthis opalescens  I,S
Enteroctopus dofleini  S
Octopus rubescens  S
Rossia pacifica  S

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This page last revised: 12-19-2021