Batrachoseps wakei Sweet & Jockusch, 2021
Arguello Slender Salamander
|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)
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).
VARIATION: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
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
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
Relation to Humans
PHYLOGENETIC RELATIONSHIPS: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).
OTHER INTERESTING INFORMATION:
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 <https://amphibiaweb.org/species/9437> University of California, Berkeley, CA, USA. Accessed Mar 22, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Mar 2023.
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