This guide was prepared by Nicole Knight. Please contact nicole.knight@mail.mcgill.ca if you have questions, notice any mistakes, or would like to contribute information to the key.
All photos taken by Nicole Knight unless otherwise indicated.
What is the purpose of this guide?
This guide is not a taxonomic key in the traditional (i.e., dichotomous) sense, which are the best tools for identifying taxa with certainty. However, taxonomic keys can be difficult to obtain and to learn to use efficiently, particularly in BC, where most information on regional species morphologies is older and scattered in a variety of often obscure sources. The intention of this work is to synthesize existing taxonomic information to create a photographic guide of local species that is (hopefully) reasonably easy to use. If you need more information, I have tried as often as possible to provide further resources with more detailed descriptions for each taxon.
What are these identifications based on?
I made the identifications in this guide based on the many useful websites out there, books in our lab and the UBC library, and work done by my labmates. I encourage users to check IDs for themselves; I have made it a point to include as many resources as possible to allow you to do so. I also ask that you contact me if you find an error so I can correct it.
Notes
These photos were taken of organisms that have been preserved in ethanol, which tends to change their coloration. Some organisms have been stained with Bengal Rose, and others may be missing appendages due to damage during collection or handling.
Order Amphipoda
I made these identifications using the Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon and volumes of the journal Amphipacifica. Excellent work has also been done by Natalie Caulk, Rebecca Best, and Jocelyn Nelson (available at http://bcbiodiversity.lifedesks.org/). Aaron Baldwin has an extensive list of amphipod species recorded in BC published here; it is well worth a look. However, because we still know (relatively speaking) very little about many local amphipod species, I was not able to narrow down every identification to the species level, and it is entirely possible that there are some errors in this guide. Because of this, I have tried to be clear about how confident I am about each identification.
Suborder Gammaridea
All photos taken by Nicole Knight unless otherwise indicated.
What is the purpose of this guide?
This guide is not a taxonomic key in the traditional (i.e., dichotomous) sense, which are the best tools for identifying taxa with certainty. However, taxonomic keys can be difficult to obtain and to learn to use efficiently, particularly in BC, where most information on regional species morphologies is older and scattered in a variety of often obscure sources. The intention of this work is to synthesize existing taxonomic information to create a photographic guide of local species that is (hopefully) reasonably easy to use. If you need more information, I have tried as often as possible to provide further resources with more detailed descriptions for each taxon.
What are these identifications based on?
I made the identifications in this guide based on the many useful websites out there, books in our lab and the UBC library, and work done by my labmates. I encourage users to check IDs for themselves; I have made it a point to include as many resources as possible to allow you to do so. I also ask that you contact me if you find an error so I can correct it.
Notes
These photos were taken of organisms that have been preserved in ethanol, which tends to change their coloration. Some organisms have been stained with Bengal Rose, and others may be missing appendages due to damage during collection or handling.
Order Amphipoda
I made these identifications using the Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon and volumes of the journal Amphipacifica. Excellent work has also been done by Natalie Caulk, Rebecca Best, and Jocelyn Nelson (available at http://bcbiodiversity.lifedesks.org/). Aaron Baldwin has an extensive list of amphipod species recorded in BC published here; it is well worth a look. However, because we still know (relatively speaking) very little about many local amphipod species, I was not able to narrow down every identification to the species level, and it is entirely possible that there are some errors in this guide. Because of this, I have tried to be clear about how confident I am about each identification.
Suborder Gammaridea
Family Eusiroidea
Pontogeneia intermedia
Distribution: Aleutian Islands to California (Encyclopedia of Life [records in the Aleutian Islands and British Columbia], accessed 3/22/2015; Light and Smith [records in California], 2007). This specimen was collected from Zostera marina, near the Hakai Beach Institute.
Telson deeply cleft (not pictured here), no accessory flagellum, rostrum does not reach more the 1/4 of the length of article 1 antennae 1. Weak posterior extension of epimeron 3. Note that in the photo on the right the organism has been stained with Bengal Rose; specimen preserved in both photos.
Pontogeneia intermedia
Distribution: Aleutian Islands to California (Encyclopedia of Life [records in the Aleutian Islands and British Columbia], accessed 3/22/2015; Light and Smith [records in California], 2007). This specimen was collected from Zostera marina, near the Hakai Beach Institute.
Telson deeply cleft (not pictured here), no accessory flagellum, rostrum does not reach more the 1/4 of the length of article 1 antennae 1. Weak posterior extension of epimeron 3. Note that in the photo on the right the organism has been stained with Bengal Rose; specimen preserved in both photos.
Pontogeneia inermis
Distribution: British Columbia to California, as well as Rhode Island to the St. Lawrence on the east coast(Encyclopedia of Life [records in British Columbia and Oregon, east coast], accessed 3/22/2015; Light and Smith [records in California], 2007). This specimen was collected in Zostera marina at Boundary Bay.
This specimen is 0.6 cm, female. Can be difficult to distinguish from its congener, P. intermedia. However, rostrum reaches >1/3 of the length of article 1 antennae 1, and epimeron 3 has a prominent posterior extension (A, B outlined for clarity), ventral corner angle of extension slightly obtuse (B), telson ends rounded (not pictured). Specimen fresh in both photos; specimen stained with Bengal Rose in A, B.
Distribution: British Columbia to California, as well as Rhode Island to the St. Lawrence on the east coast(Encyclopedia of Life [records in British Columbia and Oregon, east coast], accessed 3/22/2015; Light and Smith [records in California], 2007). This specimen was collected in Zostera marina at Boundary Bay.
This specimen is 0.6 cm, female. Can be difficult to distinguish from its congener, P. intermedia. However, rostrum reaches >1/3 of the length of article 1 antennae 1, and epimeron 3 has a prominent posterior extension (A, B outlined for clarity), ventral corner angle of extension slightly obtuse (B), telson ends rounded (not pictured). Specimen fresh in both photos; specimen stained with Bengal Rose in A, B.
Family Hyalidae
Members of the family Hyalidae are primarily found in intertidal and shallow littoral marine waters (Bousfeld and Hendrycks, 2002). Hyalidae consists of ~110 species in 12 genera; 19 species have been recorded in BC (Baldwin, >2004).
Protohyale intermedia
previously classified as Protohyale jarrettae, Hyale intermedia (Bousfield 2001; 1981)
Distribution: found from southern Alaska to Oregon (Bousfeld and Hendrycks, 2002). This specimen was found on some kelp near the Hakai Beach Institute.
Specimen shown 0.8 cm in length, not as orange as shown here (preserved). Telson fleshy and cleft, antennae 1 shorter than antennae 2, small spikes on rami (A), gnathopod 2 significantly bigger than gnathopod 1, both subchelate (B). Pereopod 5 article 5 not wider than long, 3 spines on tip of outer ramus, pereopods 6 and 7 slender and significantly longer than pereopod 5.
Members of the family Hyalidae are primarily found in intertidal and shallow littoral marine waters (Bousfeld and Hendrycks, 2002). Hyalidae consists of ~110 species in 12 genera; 19 species have been recorded in BC (Baldwin, >2004).
Protohyale intermedia
previously classified as Protohyale jarrettae, Hyale intermedia (Bousfield 2001; 1981)
Distribution: found from southern Alaska to Oregon (Bousfeld and Hendrycks, 2002). This specimen was found on some kelp near the Hakai Beach Institute.
Specimen shown 0.8 cm in length, not as orange as shown here (preserved). Telson fleshy and cleft, antennae 1 shorter than antennae 2, small spikes on rami (A), gnathopod 2 significantly bigger than gnathopod 1, both subchelate (B). Pereopod 5 article 5 not wider than long, 3 spines on tip of outer ramus, pereopods 6 and 7 slender and significantly longer than pereopod 5.
Protohyale oclairi
previously classified as Hyale oclairi (Bousfield, 1981)
Distribution: Found from southeastern Alaska to Oregon at the lower intertidal level, living in algae (Bousfield and Hendrycks, 2002). This specimen was found on Neorhodomela larix, or black pine algae, near the Hakai Beach Institute.
Specimen shown 1 cm in length. Telson fleshy and cleft and lacking an apical spine (A), antennae 1 shorter than antennae 2, gnathopod 2 significantly bigger than gnathopod 1, both subchelate (B; note that one gnathopod 2 has had its dactyl damaged during handling), large dactyls on pereopods 3-7 (1/4-1/2 propod) lacking setae but with a strong clasping spine on segment 6 (C; clasping spine circled), coxae 2 and 3 lacking posterior marginal cusp (D, specimen stained for clarity), uropod 3 uniramous.
previously classified as Hyale oclairi (Bousfield, 1981)
Distribution: Found from southeastern Alaska to Oregon at the lower intertidal level, living in algae (Bousfield and Hendrycks, 2002). This specimen was found on Neorhodomela larix, or black pine algae, near the Hakai Beach Institute.
Specimen shown 1 cm in length. Telson fleshy and cleft and lacking an apical spine (A), antennae 1 shorter than antennae 2, gnathopod 2 significantly bigger than gnathopod 1, both subchelate (B; note that one gnathopod 2 has had its dactyl damaged during handling), large dactyls on pereopods 3-7 (1/4-1/2 propod) lacking setae but with a strong clasping spine on segment 6 (C; clasping spine circled), coxae 2 and 3 lacking posterior marginal cusp (D, specimen stained for clarity), uropod 3 uniramous.
Photis brevipes
Distribution: Alaska to Baja California (Encyclopedia of Life, accessed 3/16/2015). This specimen was found living in Zostera marina near the Hakai Beach Institute.
Specimen measures ~0.4 cm in length. Fleshy, uncleft telson (not pictured), two rami on uropod 3, inner ramus smaller (also not pictured). Best identifying feature is the ornately shaped gnathopod 2, with long setae stemming from the carpus/dactyl junction, dactyl bidentate (A).
Distribution: Alaska to Baja California (Encyclopedia of Life, accessed 3/16/2015). This specimen was found living in Zostera marina near the Hakai Beach Institute.
Specimen measures ~0.4 cm in length. Fleshy, uncleft telson (not pictured), two rami on uropod 3, inner ramus smaller (also not pictured). Best identifying feature is the ornately shaped gnathopod 2, with long setae stemming from the carpus/dactyl junction, dactyl bidentate (A).
Family Hyalellidae
The Hyalellidae are herbivorous, live among aquatic plants, and are relatively helpless out of the water (Light and Smith, 2007).
Allorchestes angusta
Distribution: from southern California to the Aleutian Islands (Encyclopedia of Life, accessed 3/26/2015). This specimen was collected from some Zostera marina in Tsawwassen.
This specimen measured ~0.5 cm in length. Striking coloration, but tends to fade after only a few minutes in EtOH. Telson short and very slightly cleft (A; outlined in B), uropod 3 has a short, single ramus (A; red arrow pointing at B), simple spikes on the posterior ventral corners of pereopods 5-7 articles 4, 5.
The Hyalellidae are herbivorous, live among aquatic plants, and are relatively helpless out of the water (Light and Smith, 2007).
Allorchestes angusta
Distribution: from southern California to the Aleutian Islands (Encyclopedia of Life, accessed 3/26/2015). This specimen was collected from some Zostera marina in Tsawwassen.
This specimen measured ~0.5 cm in length. Striking coloration, but tends to fade after only a few minutes in EtOH. Telson short and very slightly cleft (A; outlined in B), uropod 3 has a short, single ramus (A; red arrow pointing at B), simple spikes on the posterior ventral corners of pereopods 5-7 articles 4, 5.
Family Ampithoidae
The Ampithoidae are herbivorous nest builders often found in algae and kelp stipes, and often assume the same colour as their habitat algae (Light and Smith, 2007).
Ampithoe lacertosa
Distribution: Ampithoe lacertosa is widely distributed; it is found from Alaska to California, as well as in Korea and Japan (Encyclopedia of Life, accessed 3/15/2015). This specimen was found living on Ulva near the Hakai Beach Institute.
Specimen measures ~2 cm in length. Telson short and fleshy; uncleft. Gnathopod 2 much larger than gnathopod 1, transverse, palm produced forward in males (A), uropod 3 biramous with two small hooks on the thicker outer ramus, inner ramus flatter and setose (B), epimeron 3 has a notch on its posterior ventral corner.
The Ampithoidae are herbivorous nest builders often found in algae and kelp stipes, and often assume the same colour as their habitat algae (Light and Smith, 2007).
Ampithoe lacertosa
Distribution: Ampithoe lacertosa is widely distributed; it is found from Alaska to California, as well as in Korea and Japan (Encyclopedia of Life, accessed 3/15/2015). This specimen was found living on Ulva near the Hakai Beach Institute.
Specimen measures ~2 cm in length. Telson short and fleshy; uncleft. Gnathopod 2 much larger than gnathopod 1, transverse, palm produced forward in males (A), uropod 3 biramous with two small hooks on the thicker outer ramus, inner ramus flatter and setose (B), epimeron 3 has a notch on its posterior ventral corner.
Ampithoe valida
Distribution: California to British Columbia, Florida to New York on the east coast, Japan; introduced from the east coast (Encyclopedia of Life, accessed 3/22/2015).
This specimen measured ~1.5 cm in length. Very similar in appearance to A. lacertosa; however, A. valida male gnathopod 2 is transverse and has a square tooth, and does not have a notch on the ventral posterior corner of epimeron 3.
Distribution: California to British Columbia, Florida to New York on the east coast, Japan; introduced from the east coast (Encyclopedia of Life, accessed 3/22/2015).
This specimen measured ~1.5 cm in length. Very similar in appearance to A. lacertosa; however, A. valida male gnathopod 2 is transverse and has a square tooth, and does not have a notch on the ventral posterior corner of epimeron 3.
Peramphithoe humeralis
Distribution: British Columbia to California (Encylcopedia of Life, accessed 3/19/2015, has it recorded only in BC, but the Light and Smith Manual lists it as a Californian species). This specimen was collected near the Hakai Beach Institute.
This magnificent beastie clocks in at a whopping 4.5 cm. Pereopod 7 much longer than pereopod 6 (A), sharp tooth present between the rami of uropod 1 (B; present on all members of Peramphithoe), article 5 of gnathopod 2 longer than article 6 (C).
Notes: This species of Peramphithoe nests in kelps by creating tubes in which they raise their young (Light and Smith, 2007).
Distribution: British Columbia to California (Encylcopedia of Life, accessed 3/19/2015, has it recorded only in BC, but the Light and Smith Manual lists it as a Californian species). This specimen was collected near the Hakai Beach Institute.
This magnificent beastie clocks in at a whopping 4.5 cm. Pereopod 7 much longer than pereopod 6 (A), sharp tooth present between the rami of uropod 1 (B; present on all members of Peramphithoe), article 5 of gnathopod 2 longer than article 6 (C).
Notes: This species of Peramphithoe nests in kelps by creating tubes in which they raise their young (Light and Smith, 2007).
Family Anisogammaridae
The members of Anisogammaridae are omnivorous and free-living (Light and Smith, 2007).
Anisogammarus pugettensis
Distribution: Aleutian Islands and SE Alaska to Northern California, low intertidal to subtidal (Bousfield, 2001). This specimen was found in Zostera japonica, a non-native eelgrass, in Tsawwassen.
This specimen, just preserved at the time it was photographed, measures ~0.8 cm in length. Male gnathopods are nearly transverse and moderately setose and gnathopod 2 is much smaller than gnathopod 1 (A), antennae 1 has a prominent accessory flagellum on the third article (B; arrow), there is a pronounced tooth on urosomite 2 (C; arrow), rami are spinose but have no setae. Note that this specimen is female; males have blunt peg spines on their gnathopod palms and gnathopod 2 is closer in size to gnathopod 1.
Notes: This species can survive in very low oxygen conditions (Bousfield 2001; Light and Smith 2007).
The members of Anisogammaridae are omnivorous and free-living (Light and Smith, 2007).
Anisogammarus pugettensis
Distribution: Aleutian Islands and SE Alaska to Northern California, low intertidal to subtidal (Bousfield, 2001). This specimen was found in Zostera japonica, a non-native eelgrass, in Tsawwassen.
This specimen, just preserved at the time it was photographed, measures ~0.8 cm in length. Male gnathopods are nearly transverse and moderately setose and gnathopod 2 is much smaller than gnathopod 1 (A), antennae 1 has a prominent accessory flagellum on the third article (B; arrow), there is a pronounced tooth on urosomite 2 (C; arrow), rami are spinose but have no setae. Note that this specimen is female; males have blunt peg spines on their gnathopod palms and gnathopod 2 is closer in size to gnathopod 1.
Notes: This species can survive in very low oxygen conditions (Bousfield 2001; Light and Smith 2007).
Family Corophiidae
Members of Corophiidae typically build U-shaped tubes in soft sediments or on hard surfaces (Light and Smith, 2007).
Monocorophium insidiosum
Distribution: West and east coasts of North America, Western Europe, and Australia (Encyclopedia of Life, accessed 3/16/2015). Non-native to BC, introduced from North Atlantic (Wonham and Carlton, 2005). Specimen collected from Tsawwassen, in Zostera marina.
These specimens, photographed shortly after preservation, measure approximately 0.4 cm in length. Notice that the female on the left is brooding; eggs are visible and attached to her ventral side. Pereopod 6 ~1/2 the length of pereopod 7 (A), rostrum extends past the ocular lobes (B; a little difficult to see), medial protrusion on antenna 2 article 1 (C; red arrow), distal medial tooth on antenna 2 article 4 (C; blue arrow).
Members of Corophiidae typically build U-shaped tubes in soft sediments or on hard surfaces (Light and Smith, 2007).
Monocorophium insidiosum
Distribution: West and east coasts of North America, Western Europe, and Australia (Encyclopedia of Life, accessed 3/16/2015). Non-native to BC, introduced from North Atlantic (Wonham and Carlton, 2005). Specimen collected from Tsawwassen, in Zostera marina.
These specimens, photographed shortly after preservation, measure approximately 0.4 cm in length. Notice that the female on the left is brooding; eggs are visible and attached to her ventral side. Pereopod 6 ~1/2 the length of pereopod 7 (A), rostrum extends past the ocular lobes (B; a little difficult to see), medial protrusion on antenna 2 article 1 (C; red arrow), distal medial tooth on antenna 2 article 4 (C; blue arrow).
Monocorophium acherusicum
Distribution: Found in Australia, Western Europe, the Northwestern Atlantic; introduced to the Northeast Pacific from the Atlantic and is now found from California to British Columbia (Encyclopedia of Life, accessed 3/22/2015). This specimen was collected from Zostera marina in Boundary Bay.
Specimen measured ~0.5 cm in length. Annoying to distinguish from congener M. insidiosum, but it has no medial tooth on antennae 2 article 4, it does have three pairs of ventral stout spines on antennae two article four, and two single spines on antennae two article five (A). Rostrum is short, and does not extend past ocular lobes (not pictured, view from above).
Distribution: Found in Australia, Western Europe, the Northwestern Atlantic; introduced to the Northeast Pacific from the Atlantic and is now found from California to British Columbia (Encyclopedia of Life, accessed 3/22/2015). This specimen was collected from Zostera marina in Boundary Bay.
Specimen measured ~0.5 cm in length. Annoying to distinguish from congener M. insidiosum, but it has no medial tooth on antennae 2 article 4, it does have three pairs of ventral stout spines on antennae two article four, and two single spines on antennae two article five (A). Rostrum is short, and does not extend past ocular lobes (not pictured, view from above).
Americorophium salmonis
Distribution: California to British Columbia (Encyclopedia of Life, accessed 3/23/2015). Unlike Monocorophium acherusicum and M. insidiosum, A. salmonis is native to the Pacific Northeast. This specimen was collected from some Phyllospadix (surfgrass) near the Hakai Institute.
This specimen measured ~0.5 cm in length. Female antennae 2 not setose, articles 3 and 4 with two small ventral spines (A; very difficult to see)
Family Aoridae
Grandidierella japonica
Distribution: native to Japan; introduced to Great Britain, Australia, and the west coast from California to British Columbia (Encyclopedia of Life, accessed 3/26/2015; Life Desks has it recorded in southern BC; accessed 3/26/2015). This specimen was collected from Zostera marina in Tsawwassen.
Male gnathopod 1 carpochelate, enormous (A), uropod 1 uniramous (unlike most species of Aoridae), spiked (B; uropod 2 damaged in photo).
Grandidierella japonica
Distribution: native to Japan; introduced to Great Britain, Australia, and the west coast from California to British Columbia (Encyclopedia of Life, accessed 3/26/2015; Life Desks has it recorded in southern BC; accessed 3/26/2015). This specimen was collected from Zostera marina in Tsawwassen.
Male gnathopod 1 carpochelate, enormous (A), uropod 1 uniramous (unlike most species of Aoridae), spiked (B; uropod 2 damaged in photo).
Aoroides columbiae
Distribution: southern California to southern Alaska (Encyclopedia of Life, accessed 3/26/2015). This specimen was collected from some Zostera marina near the Hakai Beach Institute.
Large, basket-shaped male gnathopods 1 and 2 (1 > 2; A), anterior and lateral edges of gnathopod 1 article 2 densely setose but hind margin bare, uropod 2 peduncle has a prominent ventral interramal spine.
Distribution: southern California to southern Alaska (Encyclopedia of Life, accessed 3/26/2015). This specimen was collected from some Zostera marina near the Hakai Beach Institute.
Large, basket-shaped male gnathopods 1 and 2 (1 > 2; A), anterior and lateral edges of gnathopod 1 article 2 densely setose but hind margin bare, uropod 2 peduncle has a prominent ventral interramal spine.
Suborder Caprellidea
Family Caprellidae
Members of the family Caprellidae, or skeleton shrimps, are very common at our study sites in BC, both on eelgrass and other substrates. They may be found in large blooms, particularly later in the summer, at which time they may form a thick, fouling mass on eelgrass blades and often far outnumber other invertebrate species.
Caprella laeviuscula
Distribution: British Columbia to Northern California (Encyclopedia of Life, accessed 3/18/2015).
This specimen measured ~2 cm in length, although a large range of sizes can be observed. This species is most easily distinguished from other members of Caprella by the absence of spikes on its body, particularly the head (A), and its distinctively shaped gnathopod 2 (B).
Family Caprellidae
Members of the family Caprellidae, or skeleton shrimps, are very common at our study sites in BC, both on eelgrass and other substrates. They may be found in large blooms, particularly later in the summer, at which time they may form a thick, fouling mass on eelgrass blades and often far outnumber other invertebrate species.
Caprella laeviuscula
Distribution: British Columbia to Northern California (Encyclopedia of Life, accessed 3/18/2015).
This specimen measured ~2 cm in length, although a large range of sizes can be observed. This species is most easily distinguished from other members of Caprella by the absence of spikes on its body, particularly the head (A), and its distinctively shaped gnathopod 2 (B).
Caprella californica
Distribution: California to British Columbia, Chile, SW Japan, Korea, South China Sea, Formosa Strait (Life Desks, accessed 3/18/2015). This specimen was collected from Zostera marina near the Hakai Beach Institute.
This specimen measures ~2.2 cm in length. Distinguishing features of this species include a single, large, anteriorly-pointing spine (A), no other spines on its body (although subadult and adult males have a dorsal spine on pereonite 5), and the shape of its gnathopods (B).
Distribution: California to British Columbia, Chile, SW Japan, Korea, South China Sea, Formosa Strait (Life Desks, accessed 3/18/2015). This specimen was collected from Zostera marina near the Hakai Beach Institute.
This specimen measures ~2.2 cm in length. Distinguishing features of this species include a single, large, anteriorly-pointing spine (A), no other spines on its body (although subadult and adult males have a dorsal spine on pereonite 5), and the shape of its gnathopods (B).
Caprella mutica
Distribution: native to the Sea of Japan, non-native populations found from Alaska to California, as well as in New Zealand and the UK/Europe (Ashton, 2006).
This (female) specimen measures ~2 cm in length. The species can be easily distinguished from other members of Caprella by the many spikes on its dorsal side, as well as the shape of its gnathopod 2. Species is sexually dimorphic; females tend to have spikes on anterior and posterior pereonites, including the cephalon, whereas males have spikes on posterior pereonites.
Distribution: native to the Sea of Japan, non-native populations found from Alaska to California, as well as in New Zealand and the UK/Europe (Ashton, 2006).
This (female) specimen measures ~2 cm in length. The species can be easily distinguished from other members of Caprella by the many spikes on its dorsal side, as well as the shape of its gnathopod 2. Species is sexually dimorphic; females tend to have spikes on anterior and posterior pereonites, including the cephalon, whereas males have spikes on posterior pereonites.
Caprella kennerlyi
Distribution: from Alaska to California (Life Desks; accessed 3/18/2015). This specimen was found living on some kelp near the Hakai Beach Institute.
This big fella measured 4.5 cm in length. It's distinguishable from other members of Caprella by its inflated, heavily setose antenna 1 (A), the two small anteriorly-pointed spines on its head (A), many small spines on its pereonites (B), and the shape of its gnathopod 2 (B).
Distribution: from Alaska to California (Life Desks; accessed 3/18/2015). This specimen was found living on some kelp near the Hakai Beach Institute.
This big fella measured 4.5 cm in length. It's distinguishable from other members of Caprella by its inflated, heavily setose antenna 1 (A), the two small anteriorly-pointed spines on its head (A), many small spines on its pereonites (B), and the shape of its gnathopod 2 (B).
Caprella drepanochir
Distribution: Northern California to Alaska (Encyclopedia of Life, accessed 4/21/2015). This specimen was found in a bed of Zostera japonica in Tsawwassen.
I'm not entirely confident in this identification, as the dactyls on its gnathopod 2 are smaller than what is normally seen (e.g., this photo from EOL). However, it may be that females have smaller dactyls. Any input would be appreciated. No spikes on head or body, gills more rounded than most other species of Caprella (A), gnathopod 2 lacking teeth or other ornamentation (B).
Amphipod Resources/References
Amphipacifica: Journal of Systematic Biology.
This gem of a journal was published between 1994 and 2004. It consists of three volumes that detail the distributions, phylogeny, and taxonomy of amphipods found in the Pacific Northeast. It can be difficult to get your hands on and I haven't been able to find an online copy, but there are copies in the UBC Library and BMSC Library.
-Bousfield EL (2001). The amphipod genus Anisogammarus (Gammaroidea: Anisogammaridae) on the Pacific coast of North America. Amphipacifica 3(1):29-48.
-Bousfield EL and Hendrycks EA (2002). The talitroidean amphipod family Hyalidae revised, with emphasis on the North Pacific Fauna: Systematics and distributional ecology. Amphipacifica 3(3):17-134.
-Hendrycks EA and Bousfield EL (2004). The amphipod family Pleustidae (mainly subfamilies Mesopleustinae, Neopleustinae, Pleusymtinae and Stenopleustinae) from the Pacific coast of North America: systematics and distributional ecology. Amphipacifica 3(4):45-113.
Encyclopedia of Life
In my experience, this website is primarily useful for finding distribution data.
Life Desks
This website has some fantastic photos/taxonomic descriptions/range descriptions of amphipods and caprellids published by Jocelyn Nelson and Gail Ashton, respectively; I highly recommend checking it out.
Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon (2007).
This is a great regional resource. It's not as useful here in BC, but the illustrations are fantastic for helping to understand amphipod taxonomy and often to identify which family a specimen belongs to.
Ashton GV (2006). Distribution and dispersal of the non-native caprellid amphipod, Caprella mutica Schurin 1935 (Ph.D thesis). University of Aberdeen.
Wonham MJ and Carlton JT (2005). Trends in marine biological invasions at local and regional scales: the Northeast Pacific Ocean as a model system. Biological Invasions 7:369-392.
Amphipacifica: Journal of Systematic Biology.
This gem of a journal was published between 1994 and 2004. It consists of three volumes that detail the distributions, phylogeny, and taxonomy of amphipods found in the Pacific Northeast. It can be difficult to get your hands on and I haven't been able to find an online copy, but there are copies in the UBC Library and BMSC Library.
-Bousfield EL (2001). The amphipod genus Anisogammarus (Gammaroidea: Anisogammaridae) on the Pacific coast of North America. Amphipacifica 3(1):29-48.
-Bousfield EL and Hendrycks EA (2002). The talitroidean amphipod family Hyalidae revised, with emphasis on the North Pacific Fauna: Systematics and distributional ecology. Amphipacifica 3(3):17-134.
-Hendrycks EA and Bousfield EL (2004). The amphipod family Pleustidae (mainly subfamilies Mesopleustinae, Neopleustinae, Pleusymtinae and Stenopleustinae) from the Pacific coast of North America: systematics and distributional ecology. Amphipacifica 3(4):45-113.
Encyclopedia of Life
In my experience, this website is primarily useful for finding distribution data.
Life Desks
This website has some fantastic photos/taxonomic descriptions/range descriptions of amphipods and caprellids published by Jocelyn Nelson and Gail Ashton, respectively; I highly recommend checking it out.
Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon (2007).
This is a great regional resource. It's not as useful here in BC, but the illustrations are fantastic for helping to understand amphipod taxonomy and often to identify which family a specimen belongs to.
Ashton GV (2006). Distribution and dispersal of the non-native caprellid amphipod, Caprella mutica Schurin 1935 (Ph.D thesis). University of Aberdeen.
Wonham MJ and Carlton JT (2005). Trends in marine biological invasions at local and regional scales: the Northeast Pacific Ocean as a model system. Biological Invasions 7:369-392.
Order Isopoda (Isopods)
Suborder Valvifera
Family Idoteidae
Pentidotea stenops
also known as Idotea stenops
Distribution: California to British Columbia, Yellow Sea (Encyclopedia of Life, accessed 3/19/2015). This specimen was collected from some surfgrass (Phyllospadix) near the Hakai Beach Institute.
This specimen measured ~2 cm in length. Body is significantly wider in the middle than anteriorly and posteriorly, seven pereopods, pleon composed of two complete pleonites and one incomplete pleonite and with a short posterior projection (A).
Suborder Valvifera
Family Idoteidae
Pentidotea stenops
also known as Idotea stenops
Distribution: California to British Columbia, Yellow Sea (Encyclopedia of Life, accessed 3/19/2015). This specimen was collected from some surfgrass (Phyllospadix) near the Hakai Beach Institute.
This specimen measured ~2 cm in length. Body is significantly wider in the middle than anteriorly and posteriorly, seven pereopods, pleon composed of two complete pleonites and one incomplete pleonite and with a short posterior projection (A).
Pentidotea resecata
also known as Idotea resecata
Distribution: from California to British Columbia (Encyclopedia of Life, accessed 3/20/2015). This specimen was collected from Tsawwassen in a patch of Zostera marina.
This specimen measured ~1.5 cm in length, although they are often much larger (particularly in the summer). Seven pereopods, usually green-dark brown in colour and often with a stripe running down its back, easily distinguishable from similar species by the posterior margin of its pleotelson, which is concave.
also known as Idotea resecata
Distribution: from California to British Columbia (Encyclopedia of Life, accessed 3/20/2015). This specimen was collected from Tsawwassen in a patch of Zostera marina.
This specimen measured ~1.5 cm in length, although they are often much larger (particularly in the summer). Seven pereopods, usually green-dark brown in colour and often with a stripe running down its back, easily distinguishable from similar species by the posterior margin of its pleotelson, which is concave.
Pentidotea wosnesenskii
also known as Idotea wosnesenskii
Distribution: from Baja California to the Aleutian Islands (Encyclopedia of Life, accessed 3/23/2015). This specimen was found on Phyllospadix (surfgrass) near the Hakai Institute.
This specimen measured ~1 cm in length. Seven pereopods, space in the shape of an acute angle between last pereonite and first pleonite (A, marked in blue), small protrusion on posterior margin of the pleotelson (A, red arrow), anterior margin of pereonite 1 wraps up around the cephalon (i.e., head; B).
also known as Idotea wosnesenskii
Distribution: from Baja California to the Aleutian Islands (Encyclopedia of Life, accessed 3/23/2015). This specimen was found on Phyllospadix (surfgrass) near the Hakai Institute.
This specimen measured ~1 cm in length. Seven pereopods, space in the shape of an acute angle between last pereonite and first pleonite (A, marked in blue), small protrusion on posterior margin of the pleotelson (A, red arrow), anterior margin of pereonite 1 wraps up around the cephalon (i.e., head; B).
Pentidotea montereyensis
also known as Idotea montereyensis
Distribution: California to British Columbia (Encylopedia of Life, accessed 3/23/2015). This specimen was found in Phyllospadix near the Hakai Institute.
This specimen measured at ~1 cm in length. Seven pereopods, no real space between last pereonite and first pleonite (A, blue arrow; unlike P. wosnesenskii), small protrusion on the posterior margin of the pleosome (A, red arrow), lateral edges of pereonites 2, 3 extend posteriorly (unlike P. wosnesenskii).
also known as Idotea montereyensis
Distribution: California to British Columbia (Encylopedia of Life, accessed 3/23/2015). This specimen was found in Phyllospadix near the Hakai Institute.
This specimen measured at ~1 cm in length. Seven pereopods, no real space between last pereonite and first pleonite (A, blue arrow; unlike P. wosnesenskii), small protrusion on the posterior margin of the pleosome (A, red arrow), lateral edges of pereonites 2, 3 extend posteriorly (unlike P. wosnesenskii).
Phyllodocida (Polychaetes)
Family Nereididae
Platynereis bicanaliculata
Distribution: from the Aleutian Islands to Baja California, as well as east Asia (Encyclopedia of Life, accessed 3/17/2015). Easily the most common polychaete observed at our study sites in Tsawwassen and Bamfield. These specimens were collected from Tsawwassen in patches of Zostera marina and Z. japonica.
This specimen measured ~2.5 cm in length, although they can grow to be much larger. Four eyes are present and arranged to form a trapezoid (A; live specimen), dark patches are present on the parapodia and have small protruding setae (B; this specimen was preserved in EtOH). Patterns of coloration are mostly lost in preserved specimens.
Notes: individuals of this species will fight and eat one another, as I learned while taking these photos.
Family Nereididae
Platynereis bicanaliculata
Distribution: from the Aleutian Islands to Baja California, as well as east Asia (Encyclopedia of Life, accessed 3/17/2015). Easily the most common polychaete observed at our study sites in Tsawwassen and Bamfield. These specimens were collected from Tsawwassen in patches of Zostera marina and Z. japonica.
This specimen measured ~2.5 cm in length, although they can grow to be much larger. Four eyes are present and arranged to form a trapezoid (A; live specimen), dark patches are present on the parapodia and have small protruding setae (B; this specimen was preserved in EtOH). Patterns of coloration are mostly lost in preserved specimens.
Notes: individuals of this species will fight and eat one another, as I learned while taking these photos.
Nereis sp.
Distribution: this specimen was found in a Zostera marina meadow near Bamfield, B.C.
This little guy measured only 0.3 cm in length (likely juvenile). Two pairs of eyes, two large palps, two small frontal antennae, four tentacular cirri (A). Note how the shape of the prostomium differs from Platynereis bicanaliculata.
Distribution: this specimen was found in a Zostera marina meadow near Bamfield, B.C.
This little guy measured only 0.3 cm in length (likely juvenile). Two pairs of eyes, two large palps, two small frontal antennae, four tentacular cirri (A). Note how the shape of the prostomium differs from Platynereis bicanaliculata.
Family Phyllodocidae
Eulalia sp.
This specimen measured ~1.5 cm in length. I have not been able to identify this specimen to species, but by process of elimination I think it is either E. nigrimaculata or E. macroceros. Four frontal and one medial antennae present (A; stained with Bengal Rose), proboscis thickly papillated (A).
Notes: Predatory (Light and Smith, 2007).
Eulalia sp.
This specimen measured ~1.5 cm in length. I have not been able to identify this specimen to species, but by process of elimination I think it is either E. nigrimaculata or E. macroceros. Four frontal and one medial antennae present (A; stained with Bengal Rose), proboscis thickly papillated (A).
Notes: Predatory (Light and Smith, 2007).
Anaitides sp.
also known as Phyllodoce sp.
Distribution: this specimen was collected from a Zostera marina meadow near Bamfield, BC.
This long, narrow specimen measured ~3 cm in length. Four frontal antennae present, no medial antenna, heart shaped prostomium (A). Parapodia spaced relatively far apart with leaflike cirri (B). I have not identified this specimen to species, but there are only five species of Anaitides recorded in BC (Baldwin, date of publication unknown).
also known as Phyllodoce sp.
Distribution: this specimen was collected from a Zostera marina meadow near Bamfield, BC.
This long, narrow specimen measured ~3 cm in length. Four frontal antennae present, no medial antenna, heart shaped prostomium (A). Parapodia spaced relatively far apart with leaflike cirri (B). I have not identified this specimen to species, but there are only five species of Anaitides recorded in BC (Baldwin, date of publication unknown).
Ophiurida (Brittle stars)
Family Amphiuridae
Amphipholis squamata
Distribution: cosmopolitan (Encyclopedia of Life; accessed 3/18/2015).
The arms on this specimen are ~1 cm long. Mouth is star-shaped (A), each arm segment has 3-4 pairs of short protruding spines (B).
Family Amphiuridae
Amphipholis squamata
Distribution: cosmopolitan (Encyclopedia of Life; accessed 3/18/2015).
The arms on this specimen are ~1 cm long. Mouth is star-shaped (A), each arm segment has 3-4 pairs of short protruding spines (B).
Order Decapoda
Family Epialtidae
Pugettia richii
Distribution: California to Alaska (Encyclopedia of Life, accessed 3/22/3015). This specimen was collected from some Zostera marina near the Hakai Institute.
This specimen measured ~1 cm across the carapace. Pugettia richii, or the cryptic kelp crab, is distinguished by the teeth projecting from its carapace. These crabs often decorate themselves with algae or other materials.
Class Gastropoda
Family Aplysiidae
Phyllaplysia taylori
Distribution: Central British Columbia to Northern Mexico (Life Desks, accessed 3/22/2015).
Phyllaplysia taylori is easily recognized by its bright colouring and black and white stripes on its dorsal side.
Family Aplysiidae
Phyllaplysia taylori
Distribution: Central British Columbia to Northern Mexico (Life Desks, accessed 3/22/2015).
Phyllaplysia taylori is easily recognized by its bright colouring and black and white stripes on its dorsal side.
Family Littorinidae
Lacuna vincta
Distribution: Cosmopolitan in the Northern Hemisphere, also found in the southern half of South America (Encylopedia of Life, accessed 3/22/2015). These specimens were collected from Zostera marina near the Hakai Beach Institute.
These specimens range widely in size and relative height/width depending on age. Coloration and pattern also differs between individuals, some are banded whereas other are a solid brown or gold colour. Note that the juveniles are far less oblong than the adults.
Lacuna vincta
Distribution: Cosmopolitan in the Northern Hemisphere, also found in the southern half of South America (Encylopedia of Life, accessed 3/22/2015). These specimens were collected from Zostera marina near the Hakai Beach Institute.
These specimens range widely in size and relative height/width depending on age. Coloration and pattern also differs between individuals, some are banded whereas other are a solid brown or gold colour. Note that the juveniles are far less oblong than the adults.
Family Haminoeidae
Haminoea japonica
a.k.a. Japanese bubble snail
Distribution: California to British Columbia, native to Japan (Encyclopedia of Life, accessed 4/21/2015). This specimen was collected from a mixed meadow of Zostera japonica and Zostera marina at Boundary Bay.
This specimen measures at ~1 cm in length. The shell is globose, thin, and translucent, whereas the body is dark and mottled. The posterior of the head shield is deeply notched (shell slightly damaged but notch visible; A).
Notes: Herbivorous, feeds primarily on diatoms (Malaquias et al., 2004, 2009). Produces some swimming swimming, non-feeding veliger larvae as well as crawling juveniles (Gibson and Chia, 1989, 1995).
Haminoea japonica
a.k.a. Japanese bubble snail
Distribution: California to British Columbia, native to Japan (Encyclopedia of Life, accessed 4/21/2015). This specimen was collected from a mixed meadow of Zostera japonica and Zostera marina at Boundary Bay.
This specimen measures at ~1 cm in length. The shell is globose, thin, and translucent, whereas the body is dark and mottled. The posterior of the head shield is deeply notched (shell slightly damaged but notch visible; A).
Notes: Herbivorous, feeds primarily on diatoms (Malaquias et al., 2004, 2009). Produces some swimming swimming, non-feeding veliger larvae as well as crawling juveniles (Gibson and Chia, 1989, 1995).
Class Bivalvia
Order Veneroida
Family Cardiidae
Clinocardium nuttallii
Distribution: Japan, Russia, Pacific Northeast from California to the Aleutian Islands (Encyclopedia of Life, accessed 3/26/2015). This specimen was found in the high intertidal, in a mixed Zostera marina/Zostera japonica meadow at our Tsawwassen site.
Specimen measured just over 1 cm in width, and ~0.6 cm in height. Likely juvenile, adults tend to have very high shells. Radial ribs that become interlocking undulations at the ventral margins of the valves (A), 2 adductor muscle scars of nearly equal size (B; difficult to see), hinge teeth (C).
Order Veneroida
Family Cardiidae
Clinocardium nuttallii
Distribution: Japan, Russia, Pacific Northeast from California to the Aleutian Islands (Encyclopedia of Life, accessed 3/26/2015). This specimen was found in the high intertidal, in a mixed Zostera marina/Zostera japonica meadow at our Tsawwassen site.
Specimen measured just over 1 cm in width, and ~0.6 cm in height. Likely juvenile, adults tend to have very high shells. Radial ribs that become interlocking undulations at the ventral margins of the valves (A), 2 adductor muscle scars of nearly equal size (B; difficult to see), hinge teeth (C).
Eggs
Clupea pallasii (Pacific herring)
We found these eggs during a spawning event (late March) all over the Zostera marina and Z. japonica at our study site in Tsawwassen (especially in the high intertidal and on Z. japonica).
Clupea pallasii (Pacific herring)
We found these eggs during a spawning event (late March) all over the Zostera marina and Z. japonica at our study site in Tsawwassen (especially in the high intertidal and on Z. japonica).
Melibe leonina (Nudibranch)
We observed these (white and orange) eggs in abundance during a Melibe spawning event in late March in the low intertidal/subtidal.
We observed these (white and orange) eggs in abundance during a Melibe spawning event in late March in the low intertidal/subtidal.
Project Zostera UBC Invertebrate Key by Nicole Knight is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.