AmphibiaWeb - Batrachoseps wakei
Batrachoseps wakei
Arguello Slender Salamander
Subgenus: Batrachoseps
family: Plethodontidae
subfamily: Hemidactyliinae
genus: Batrachoseps
Species Description: Sweet SS and Jockusch EL 2021. A New Relict Species of Slender Salamander (Plethodontidae: Batrachoseps) with a Tiny Range from Point Arguello, California. Ichthyology & Herpetology, 109(3), 836-850.

© 2021 Robert W. Hansen (1 of 2)
Conservation Status (definitions)
IUCN (Red List) Status
NatureServe Status Use NatureServe Explorer to see status.
National Status None
Regional Status None



View distribution map in BerkeleyMapper.

Batrachoseps wakei is a relatively large salamander compared to other species in its genus, as the snout vent length of the largest male is 65.0 mm and the snout vent length of the largest female is 67.6 mm. Batrachoseps wakei have a rounded head that is indistinguishable from the neck, and the eyes can be seen bulging out when the species is looked at from a ventral view. The snout is projected 0.4 mm beyond the mandible. The pattern of skin grooves on the head is typical for its genus. The head width is about 66% of the length of the hindlimb for males, and is about 70% for females. The depth of the head from a posterior angle at the jaw is 72% of the head width. The distance between the snout and gular fold is 17% of the snout vent length. The distance between the external nares is 37% of the head width. The eyelid is slightly longer than wide, and the eyelid width is about 31% of the head width. The orbit diameter is about the same as the eyelid width. The distance between the anterior rim of the orbit to the snout is 90% of the orbital diameter. The distance from the snout to the forelimb insertion is 21% of the snout vent length. The hind limb length is about 16% of the snout vent length in males, and is about 15% in females. As body size increases, relative tail length increases, as well, from 57% of the snout vent length at 21 mm to 127% of the snout vent length in the largest male and 137% of the snout vent length in the largest female. The width of the right hand is 20% of the forelimb length and the width of the right foot is one third the length of the hindlimb. The length of the third toe is almost half the length of the foot. The body width from behind the forelimbs is 66% of the length of the forelimb. The axilla to groin length is about 63% of the snout vent length. Most B. wakei have 22 trunk vertebrae (21 costal grooves), but some have 21 trunk vertebrae (20 costal grooves). Between adpressed limbs there are about 9 costal grooves. There is no mental gland or postillac gland (Sweet and Jockusch 2021).

Batrachoseps wakei is part of the genus Batrachoseps because of its four toes on the hind feet, its big dorsal fontanelle in the skull, and general genetic attributes. This salamander species is assigned to the Batrachoseps subgenus. It is differentiated from members of the Plethopsis subgenus (such as B. campi, B. robustus, and B. wrighti) by having more trunk vertebrae and fused premaxillary bones (Sweet and Jockusch 2021).

Batrachoseps wakei is a member of the B. pacificus group, and is similar to other species such as B. major and B. pacificus in that it has a large body size, a medium brown ground color on the dorsal, a dorsal pattern of longitudinally vermiculate tan marks, a few white iridescent chromophores on the dorsal or ventral surface, usually some orange patches on the distal tail, and a pale ventrum. It is different in that B. wakei generally have a smaller head, eyes protruding laterally beyond the margin of the upper jaw, 50% fewer melanophores on the throat and chest, more extensive patches of orange on the distal half of the tail, and no melanophores in the peritoneal lining. As for genetic attributes, B. wakei has a longer tail than B. pacificus. Batrachoseps wakei also differ from B. major in that they have proportionally longer limbs, larger feet, and a shorter tail. Batrachoseps wakei differ from B. m. aridus, a subspecies of B. major, in that B. wakei have a proportionally smaller head and a longer tail. Batrachoseps wakei also have a pale ventral trunk and a pattern of pale longitudinal vermiculations on the dorsum as opposed to the B. m. aridus’s dense suffusion of gold and silver iridescent chromophores (Sweet and Jockusch 2021).

To the north, in central, coastal California, other species in the B. pacificus group such as B. gavilanensis, B. incognitus, B. luciae, and B. minor can be found. These species are smaller as a whole, with smaller heads, shorter limbs, narrower feet, and longer tails. These species are also darker than B. wakei dorsally and ventrally, and their venter is usually dark gray or black with visible white guanophores (Sweet and Jockusch 2021).

In the central and eastern Transverse Ranges, another species of the B. pacificus group, B. gabrieli, can be found. Batrachoseps gabrieli is smaller and darker, with a narrower head, a smaller limb interval resulting from longer limbs, and a long, thin tail. They typically have coppery markings on the dorsum (Sweet and Jockusch 2021).

Batrachoseps nigriventris can be found in the same geographical areas as B. wakei; however, B. nigriventris avoids the coastal terrace as opposed to B. wakei. Batrachoseps wakei is generally larger, with a proportionally larger head, limbs, and feet. It also has a proportionally shorter tail, and a pale ventral trunk and tail. Similarly Batrachoseps wakei differs from B. attenuatus and B. gregarius in the same ways as it differs from B. nigriventris (Sweet and Jockusch 2021).

Some other species in the subgenus Batrachoseps are found in the Tehachapi Mountains and Sierra Nevada and are unlikely to be confused with B. wakei. Most of these are much smaller than B. wakei, with the only exception being B. stebbinsi, which have 18 - 19 trunk vertebrae (compared to 21 - 22), longer limbs, and larger feet. The other smaller species are B. bramei, the B. diabolicus group (B. altasierrae, B. diabolicus, B. kawia, B. regius), B. simatus, and B. relictus. Batrachoseps simatus has a similar vertebral number and dorsal pattern to B. wakei, however it is more slender with proportionally smaller feet, a longer but thinner tail, and a medium gray venter (compared to light tan). Batrachoseps bramei has a proportionally longer head and fewer trunk vertebrae (18 - 19) compared to B. wakei. Batrachoseps relictus has proportionally shorter limbs, smaller feet, and a longer tail than B. wakei. The B. diabolicus group all have a snout vent length of less than 50 mm and are relatively slender. They have shorter limbs, relatively small feet, and proportionally longer tails (Sweet and Jockusch 2021).

In alcohol, B. wakei coloration on the dorsum is a solid medium brown color. It is slightly darker on the head and on the dorsal third of each costal groove. The openings around the skin glands are darker rings that get slightly lighter on the upper side and completely cut off at the ventrolateral line. There are fewer and smaller dark spots on the ventrum of the B. wakei, and on the midline of the ventral these darker spots are almost absent. There is more dark pigmentation on the pectoral region, as well as along the cloacal lips and the ventral side of the tail. The limbs’ colorations are similar to the rest of the body, being dark on top and paler ventrally. The iris is dark colored, and the eyelids are darker around the edge (Sweet and Jockusch 2021).

Coloration in life is based on the examination of 26 individuals, including three small juveniles. The background color of the dorsum is light brown. The color on the dorsum is made up of many dots of color, mostly brown but also mixed in with darker spots and lighter spots. At the ventrolateral line, these spots become less dense. The ventral surface has few melanophores, and the background color is light tan with a light orange on the tail. The iris of the salamander’s eyes is black, and there are two thin golden arcs bordering the dorsal third of the pupil. On the snout, anterior half of the eyelids, and lateral surface of the face, neck, and trunk there are tiny white guanophores. On the neck, trunk, and tail there are tan to dull golden iridescent chromophores spread out in longitudinal streaks that are less concentrated on the dorsal midline. These chromophores form irregular pale dorsolateral bands. Overlying these bands are patches of orangish copper iridescent chromophores that become denser and larger posteriorly on the dorsum of the tail. Larger individuals have larger orange patches, and some large adults may have orange cover the entire dorsum surface of the distal third of the tail. This holds true for both female and male salamanders. Usually B. wakei have small orange patches dorsally on the thighs. Juveniles are solidly dark brown on the dorsum and tan on the ventral surface. They have no orange patches but they have dense white chromophores on all lateral surfaces (Sweet and Jockusch 2021).

Female B. wakei are slightly larger than males, as the largest female specimen’s snout vent length was 67.6 mm and the largest male was 65.0 mm. There is also variation in the number of trunk vertebrae, as some B. wakei have 21 but most have 22. The orange patches on the tail can also vary, as juveniles have no orange patches and smaller specimens have smaller orange patches (Sweet and Jockusch 2021).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: California


View distribution map in BerkeleyMapper.
Batrachoseps wakei can be found in Santa Barbara County, California, U.S.A, restricted to Point Arguello in a zone that is no more than 400 m wide and 4 km long. Its range is a coastal marine terrace that runs from the south rim of the coastal cliffs of Honda Canyon to old railroad siding north of Rocky Point. The elevation range is 20 – 60 meters.

Batrachoseps wakei have been found at four sites within this zone. The first site is 0.5 km southeast of Arguello Coast Guard Station, along the Union Pacific Railroad railroad tracks. The second site is Point Arguello, which is in the vicinity of the abandoned Coast Guard Station. The third site was 0.9 km north-northeast of Arguello Coast Guard Station along the railroad tracks. The last site was at Honda Point, also known as Point Pedernales. This general area juts out west into the Pacific Ocean, which results in strong but very local onshore fog, winds and rainfall. The ground is primarily made of beach sand deposited on the terrace and decomposition of vegetation, forming a dark sandy loam soil that can hold burrows. The vegetation is thick and low, and dominated by non-native Iceplant (Carpobrotus edulis), but includes some vegetation of the arborescent Giant Coreopsis, Leptosyne gigantea. This type of habitat is not found elsewhere on the coastal terraces. To the north, the coast is mostly dune fields, and to the south of Point Conception, there is much less fog and rainfall. At Point Arguello, the crest of the western end of the Santa Ynez Range is composed of early Miocene rhyolitic tuffs of the Tranquillon Volcanics Formation. These sedimentary rocks overlay two deepwater marine deposits, the Rincon Shale and Monterey Formation. The rocks at Honda Point (also named Point Pedernales) are composed of Tranquillon volcanics. To the south, Point Arguello is underlain by Monterey shale (Sweet and Jockusch 2021).

Life History, Abundance, Activity, and Special Behaviors
Since B. wakei has been found in sympatry with B. nigriventris (which has been found in sympatry with B. gabrieli, B. pacificus, B.major, B. minor, B. incognitus, and B. gavilanensis), it is likely B. wakei is in sympatry with the other species where their habitats meet. The frog Pseudacris hypochondriaca and plethodontid salamanders Aneides lugubris and Ensatina eschscholtzii, are each micro-sympatric with B. wakei. Among lizards, Sceloporus occidentalis, Plestiodon skiltonianus, Elgaria multicarinata, and Anniella pulchra are micro-sympatric with B. wakei. As for snakes, Diadophis punctatus and Pituophis catenifer annectens have been found on-site, with Crotalus helleri nearby (Sweet and Jockusch 2021).

Regenerating tails have only been seen in 2 of 32 specimens, and regenerating limbs in only 1 of 32 specimens (Sweet and Jockusch 2021).

Trends and Threats
The expected population size of B. wakei is small, as there is little genetic variation and has a small range. Since the effective population size is likely very low and the species has a small range size, B. wakei may be an “Endangered” species. Small range size in particular is a major predictor of endangerment, and B. wakei is at the extreme lower end of amphibian range sizes, falling in the bottom 1%. For several years, after this species was discovered, surrounding areas have been searched for B. wakei, but the known range of the species is still small. However, in this small range, B. wakei are of moderate abundance and can be consistently found. This leads to the conclusion that further search for B. wakei might be successful in similar coastal areas. Despite the lack of genetic diversity and small range in B. wakei, the species is well protected and likely to persist as long as habitat is not disrupted. A non-native, invasive Iceplant species has developed and strongly impacts plant life in this region; however, the Iceplant does not seem to negatively affect the salamanders. In fact, B. wakei may benefit from the increased retention of surface moisture (Sweet and Jockusch 2021).

Relation to Humans
The land B. wakei lives on is owned by the United States Space Force, the U.S. Coast Guard, and the Union Pacific Railroad Corporation. These government entities are likely to be supportive of conservation of this species. Currently, most of the habitat of B. wakei is in undeveloped dunes. None of their habitat is accessible to the general public (Sweet and Jockusch 2021).


Using Maximum Likelihood and Bayesian Inference on CytB, Rag-1, gadph, pomc, pvalb, mylpf, and ilf3 DNA sequences showed consistent phylogenetic results for B. wakei. Batrachoseps wakei is sister to the clade composed of B. pacificus and B. major. Batrachoseps luciae is the next most closely related species (Sweet and Jockusch 2021).

Batrachoseps wakei is named in honor of the late David Burton Wake, Professor Emeritus and former Director of the Museum of Vertebrate Zoology at the University of California, Berkeley, and AmphibiaWeb Founder and Director. He has made great contributions to the research of California salamanders and general amphibian conservation and taxonomy. Using the most current analytical techniques, David Wake revealed much complexity of the genus Batrachoseps, and had a part in discovering or naming most of the 22 species in the genus. David Wake nurtured the museum’s focus on discovering the diversity and evolutionary history of western North American tetrapods. He also played a critical role in warning the declining amphibian crisis. He founded this website, AmphibiaWeb, to promote a collaborative vision for the amphibian research community and to make high quality information about amphibians accessible to all (Sweet and Jockusch 2021).

There is little genetic variation in B. wakei. In five out of the seven genetic markers analyzed (both mitochondrial and nuclear), only two had any variation. The two markers with variation were Rag1 and gadph (Sweet and Jockusch 2021).


Sweet, S. S., Jockusch, E. L. (2021). "A new relict species of Slender Salamander (Plethodontidae: Batrachoseps) with a tiny range from Point Arguello, California." Ichthyology & Herpetology, 109(3), 836-850. [link]

Originally submitted by: Jessica Pan (2021-10-28)
Description by: Jessica Pan (updated 2021-10-28)
Distribution by: Jessica Pan (updated 2021-10-28)
Life history by: Jessica Pan (updated 2021-10-28)
Trends and threats by: Jessica Pan (updated 2021-10-28)
Relation to humans by: Jessica Pan (updated 2021-10-28)
Comments by: Jessica Pan (updated 2021-10-28)

Edited by: Ann T. Chang, Michelle S. Koo (2021-11-11)

Species Account Citation: AmphibiaWeb 2021 Batrachoseps wakei: Arguello Slender Salamander <> University of California, Berkeley, CA, USA. Accessed May 18, 2022.

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Citation: AmphibiaWeb. 2022. <> University of California, Berkeley, CA, USA. Accessed 18 May 2022.

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