Description
There have been two descriptions of Bolitoglossa morio. The original holotype was described by Cope in 1869, but was lost and never again relocated (Campbell et al. 2010). A neotype was described by Campbell et al. in 2010, and it was chosen based on similarity of coloration and size compared to the Cope (1869) holotype. The snout vent length of the holotype is 49.27 mm. The snout vent of the samples collected by Campbell et al. (2010) ranged from 52.6 - 55.0 mm in females, and 40.9 - 44.4 mm in males. The head is flat, and the snout is slightly truncated and extends past the mandible. The costal grooves are equal on both sides, and folds are also found behind the eyes, but they are not extremely distinct (Cope 1869). When adpressed, the limbs of B. morio have one or two costal grooves in between them. The feet are broader than the hands. All toes except the first, which has no webbing, have moderate webbing that extends to the distal phalanges (Campbell 2010). The free tips of the digits have are broad and truncated. The subdigital pads are distinct. The vent and the tail both have folds, and the tail is thick, round, and tapered (Cope 1869, Campbell 2010).

At the time of its description, B. morio was thought to be a member of the now defunct Geotriton genus, and a small diagnosis was provided comparing B. morio to two of its congeners: G. carbonarius, now B. platydactyla, and G. fuscus, now Salamandra atra. Bolitoglossa morio differs from B. platydactyla, by having free terminal phalanges, a shorter body, and different coloration. Bolitoglossa morio differs from S. atra by having a narrower head, whereas the head of S. atra is quite flat. The folds behind the eye are similar to those of S. atra, but are less distinct (Cope 1869).

Bolitoglossa morio is assigned to the subgenus Magnadigita due to its moderate size, and digits that lack full webbing. Males of B. morio have a prominent mental gland, which is another defining characteristic of the Magnadigita subgenus. Also, this subgenus is localized in Nuclear Central America, as is B. morio (Parra-Olea et al. 2004).

Bolitoglossa morio is smaller than B. mexicana, B. dofleini, B. meliana, and B. lincolni, and larger than B. rufescens, B. veracrucis, and B. rostrata. It has a shorter tail than B. mexicana and B. dofleini, and a longer tail than B. franklini and B. rostrata. Bolitoglossa morio also has smaller hands and feet than B. mexicana, B. dofleini, B. franklini, and B. engelhardti, and larger hands and feet than B. veracrucis, B. flavimembris, and B. rostrata (Campbell et al. 2010).

The coloration of B. morio differs from B. meliana, which is uniformly black including the flanks and venter, B. lincolni and B. franklini, which have distinct dorsal patterns of red, yellow, or green, and B. engelhardti, which has a brown dorsal color with small flecking or streaks (Campbell et al. 2010).

Bolitoglossa morio differs from B. omniumsanctorum by having slightly longer legs, a lighter coloration, and a smaller number of vomerine teeth. Also, B. omniumsanctorum always has pinkish coloration across its flanks, while B. morio does not (Campbell et al. 2010).

In life, the dorsal ground coloration of B. morio is quite diverse (Campbell et al. 2010). The original description stated that B. morio is black on the dorsal side of its body, and leaden black on the ventral side. The ventral sides and outer faces of limbs are mottled with indistinct whitish dots (Cope 1869). This is reiterated by Campbell et al. (2010) describing the lateral surfaces from the jaw to the vent as covered with orange blotches. The ventral surface of the tail is black and has orange flecking. The hind limbs also have heavy orange flecking (Campbell et al. 2010). It is unclear if these descriptions are in life or in preservative.

In formalin, the skin secretion of B. morio turned orange (Campbell et al. 2010).

Campbell et al. (2010) collected specimens of B. morio from 1993 to 2001, and found sexual dimorphism in the species. Females of B. morio, which ranged from 52.6 to 55.0 mm, tend to be much larger than males, which ranged from 40.9 to 44.4 mm. There are also nearly twice as many maxillary and premaxillary teeth in females than in males, which ranged from 28 to 33 teeth, as opposed to the female range of 50 to 54 teeth. Additionally, there is variation between individuals in the dorsal ground coloration of B. morio (Campbell et al. 2010).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Guatemala

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (5 records).

Bolitoglossa morio is endemic to southwestern and southeastern Guatemala, and the elevation range it lives in is 1400 to above 2500 m. It inhabits much of the Guatemalan Plateau, which is recognized as the Chimaltenagan subarea. It lives in dry subtropical montane forests, but also in pine forests and humid broadleaf forests that border cloud forests. Individuals have been found in logs, under oaks, and even in bromeliads (Acevedo et al. 2008, Campbell et al. 2010).

Life History, Abundance, Activity, and Special Behaviors
All members of the Bolitoglossa genus are nocturnal, and seek refuge in hiding places like bromeliads, during the day (Ruano-Fajardo et al. 2014).

A study was done in 2014 on the relationship between salamander size, and six different variables of bromeliad characteristics, in order to observe bromeliad selection by B. morio and other Guatemalan salamanders. It was found that larger salamanders in all observed species including B. morio preferred bromeliads with higher pH’s, larger phytotelmata, and cooler water. It was also found that B. morio and B. pacaya are sympatric in the same bromeliads species. In fact, out of the seven bromeliads containing B. pacaya individuals, six of them also contained B. morio individuals. The study concluded that salamanders of B. morio did not select bromeliads randomly. Their ability to select bromeliads with more favorable characteristics, such as water retention and higher humidity levels, provides them with a less variable microclimate and helps them to survive in such extreme Guatemalan conditions, especially during the dry season (Ruano-Fajardo et al. 2014).

Trends and Threats
Although Bolitoglossa morio seems to adapt to its environment quite well, it is likely suffering from general habitat loss, urbanization, logging, wood harvesting, and deforestation (Acevedo et al. 2008).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Urbanization

Comments
Until 1963, the Bolitoglossa genus was only separated into two subgenera, Magnadigita and Bolitoglossa, but Wake and Brame (1983) demonstrated that this representation was inaccurate, and so Parra-Olea et al. (2004) proposed a new phylogenetic tree for the genus. The Bayesian Inference and Maximum Likelihood analyses of the 16S and cyt b mitochondrial genes for their study resulted in three nearly equally parsimonious trees. However, one tree had slightly more confidence. According to this tree, B. morio belongs to the Magnadigita subgenus of Bolitoglossa, and is described as follows: Bolitoglossa morio is most closely related to B. flavimembris. However, results show that B. flavimembris is more closely related to one specimen of B. morio than the two B. morio specimens are to each other. The clade formed by B. morio and B. flavimembris is sister with the clade formed by B. carri, B. conanti, B. diaphora, and B. dunni, indicating B. morio is part of the B. dunni species group (Parra-Olea et al. 2004).

Bayesian Inference and Maximum Likelihood analyses of the 16S and cyt b mitochondrial genes were also done on the Bolitoglossa (Magnadigita) genus in 2014. According to analyses, B. morio is sister to B. kaqchikelorum. The clade formed by these two species is sister to a clade formed by B. suchitanensis and B. eremia. The clade formed by these four species is sister to B. flavimembris. The clade formed by these five species is closely related to three other clades: one clade formed solely by B. tenebrosa, one clade formed by B. carri, B. dunni, B. diaphora, B. conanti, and B. oresbia, and finally a clade formed by B. heiroreias, B. celaque, and B. synoria. However, the resolution on their relationships is low (Vásquez-Almazán et al. 2014).

There has been much contention about the synonymy of B. omniumsanctorum and B. morio, since in 1983, Wake and Elias (1983) placed the former into B. morio based on similar size, form, and coloration. However, Campbell et al. (2010) found that B. omniumsanctorum had significant differences from B. morio, by having relatively shorter legs, darker coloration, and a greater amount of vomerine teeth. This confusion may have occurred due to the subtlety of the differences to the naked eye. Also, the coloration of B. omniumsanctorum is usually quite distinct, as it has extensive pinkish coloration on its flanks. However, the dorsal ground coloration of B. morio is quite diverse, so a diagnosis based on coloration was not of any great value. Now, B. omniumsanctorum is regarded as an individual species (Campbell et al. 2010).

References

Acevedo, M., Wake, D., Papenfuss, T., Vasquez, C., Rovito, S. & Elias, P. 2008. Bolitoglossa morio. The IUCN Red List of Threatened Species 2008: e.T59183A11882680.

Campbell, J. A., Smith, E. N., Streicher, J., Acevedo, M. E., Brodie, E. D. Jr. (2010). "New salamanders (Caudata: Plethodontidae) from Guatemala, with miscellaneous notes on known species." Miscellaneous Publications Museum of Zoology University of Michigan, 200, 1-66. [link]

Cope, E. D. (1869). ''A review of the species of Plethodontidae and Desmognathidae.'' Proceedings of the Academy of Natural Sciences of Philadelphia, 21, 93-118.

Parra-Olea, G., García-París, M., Wake, D. B. (2004). ''Molecular diversification of salamanders of the tropical American genus Bolitoglossa (Caudata: Plethodontidae) and its evolutionary and biogeographical implications.'' Biological Journal of the Linnean Society, 81, 325-346.

Ruano-Fajardo, G., Rovito, S. M., Ladle, R. J. (2014). ''Bromeliad selection by two salamander species in a harsh environment.'' PLos ONE

Vasquez-Almazan, C. R., Rovito, S. M. (2014). ''A New Species of Black Bolitoglossa (Caudata: Plethodontidae) from Guatemala.'' Journal of Herpetology, 48, 518-524. [link]

Wake, D. B., and Elias, P. (1983). ''New genera and a new species of Central American salamanders, with a review of the tropical genera (Amphibia, Caudata, Plethodontidae).'' Contributions of the Natural History Museum of Los Angeles County, 345, 1-19.

Species Account Citation: AmphibiaWeb 2021 Bolitoglossa morio: Cope's Mushroom-tongue Salamander <https://amphibiaweb.org/species/3992> University of California, Berkeley, CA, USA. Accessed Nov 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Nov 2024.

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