Rena dulcis , also known commonly as the Texas blind snake , the Texas slender blind snake , or the Texas threadsnake  , is a species of snake in the family Leptotyphlopidae. The species is endemic to the Southwestern United States and adjacent northern Mexico. Three subspecies are currently recognized, including the nominate subspecies described here. The Texas blind snake appears much like a shiny earthworm. It is pinkish-brown puce in color with a deep sheen to its scales.
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Leptotyphlops dulcis has an extensive range, from the Nearctic region to the Neotropics. In the United States, L. Ernst and Ernst, ; Smith, et al. Texas blind snakes can be found in arid grasslands and desert fringes as long as moisture and surface cover, such as rocks and logs, are available. They can be found from sea level to roughly m. Plant species that are prevalent in preferred habitat include yucca, cacti, and thornbush.
It is common to find these snakes in prairie grasslands and oak-juniper woodlands, as well as on canyon bottoms and rocky hillsides. Texas blind snakes have been known to take advantage of water sources and compost piles common in suburban settings. Ernst and Ernst, Texas blind snakes are fossorial.
They live in a variety of habitat types, as long there is ample food and loose, moist soil. These snakes have been found in arboreal habitats as well in several cases involving following their ant prey, as well as occasionally being deposited in nests by screech owls. Texas blind snakes sometimes follow earthworm trails, a behavior which is assumed to be linked to its lack of specialized digging modifications prevalent in other fossorial reptiles, as this snake does not eat earthworms.
If given a choice, clay-loam soils are preferred over other types. Ernst and Ernst, ; Gehlbach and Baldridge, ; Gehlbach, et al. Texas blind snakes are small snakes. Length ranges from 10 to 30 cm. They are 4 to 5 mm in diameter, have small, uniform, smooth scales, blunt heads, and reduced eyes. Color varies from reddish brown to pink or gray with most pigment in the seven most dorsal scale rows. There are 14 anterior and midbody rows, 12 rows anterior to the vent, and 10 rows around the tail, with a total of to middorsal scales.
They have an undivided anal plate. Leptotyphlops dulcis can be distinguished from Leptotyphlops humilis because it has supraocular scales between the eyes, thus creating a total of three scales between the oculars one prefrontal and the two supraocular. Leptotyphlops dulcis has no teeth on the maxilla, only on the anterior half of the lower jaw. Cochran, ; Ernst and Ernst, There is no apparent sexual dimorphism in Texas blind snakes and dissection of the tail is necessary to determine gender.
There are four subspecies, two are found north of Mexico: L. Males follow female pheromone trails to find mates. Mating occurs under a rock or in a crevice and the male wraps himself around the female in a corkscrew shape.
Because Texas blind snakes live largely underground, little information is available regarding their reproductive behavior. The mating period occurs from late March to June in Texas. While age at reproduction is not known for females, size has been noted. Females averaging Interestingly, females only possess a right oviduct with well-developed seminal receptacle and a short vaginal pouch.
While not much is known regarding the ovarian cycle of these snakes, but females have been found containing developed eggs in early summer, which suggests spring ovulation and late summer oviposition. Ernst and Ernst, ; Goldberg, Males possess a single, smooth hemipenis that is not distally forked and the sulcus spermaticus is deeply grooved. Additionally, males have spindle-shaped testes at the front caudal third of the body. The left testis usually has fewer lobes than the right testis, usually four to six lobes.
While the testicular cycle has not been determined, it is probably similar to that of Leptotyphlops humilis. Texas blind snakes nest in cracks in the earth, roughly 0. In these colonies, snakes sit atop the clutches of eggs, including multiple clutches in layers. Eggs are long and narrow 15mm by 4.
Hatching occurs in the fall, late August to September, with roughly 7 cm pink hatchlings emerging. No data on lifespan are available. Texas blind snakes are secretive and difficult to observe because of their fossorial habits.
Warmer climates correlate to longer emergence periods ranging from May to October in this species. Very low humidity and high temperatures can trigger aestivation deep underground, where they commonly hibernate during the winter. Texas blind snakes are nocturnal, becoming active on the surface only at night with the exception of occasionally on cool or rainy days.
They prefer temperatures between Texas blind snakes are slow moving, at about 1. They sometimes use their tail to lever themselves forward. There is no information on home range size in Texas blind snakes. Texas blind snakes are not blind.
Although their eyesight is greatly reduced, they are able to distinguish changes in light intensity. They communicate both interspecifically, as well as intraspecifically, through the use of attractant and deterrent pheromones.
The primary food source for these snakes are ant and termite larvae, which they often find by foraging in colonies of these social insects. Texas blind snakes are known for foraging amidst colonies of army ants Neiv amyrmex nigrescens. Normally, these ants attack threats, but Texas blind snakes are able to produce cloacal secretions, consisting of glycoproteins with free fatty acids, that act as a deterrent toward the ants and allow them to go unharmed in colonies. Additionally, these snakes are attracted to the pheromones that army ant workers secrete.
They are also able to use cloacal secretions as an interspecific signal to deter ophiophagus snakes. Finally, the secretions serve as intraspecific signals as well, in that other blind snakes of both sexes are attracted to them. Other soft-bodied larval and nypmhal arthropods are also consumed opportunistically. They have been shown to eat the eggs of these insects as well. One hypothesis regarding their choice of soft-bodied prey over adult arthropods is that the chitonous bodies of adult ants and the heads of termites could potentially be harmful to the blind snake digestive system, although this has not been confirmed.
Ernst and Ernst, ; Punzo, ; Smith, et al. Through the use of olfaction, these blind snakes are able to detect pheromones in the trails of species such as army ants.
Often these snakes will move in a concertina or lateral undulatory motion until they encounter those trails, at which time they perform a combination of touching the external nares to the trail, pausing for up to a minute, and flicking the tongue rapidly.
Ernst and Ernst, ; Gehlbach, et al. The family Leptotyphlopidae , which includes Texas blind snakes, however, possess a much different mechanism of prey-consumption modes.
Rather than employ the maxilla in driving prey down the digestive tract, they incorporate the lower jaw in a process called mandibular raking. In this mechanism, they uses bilaterally synchronous motions of the toothed lower jaw to consume soft-bodied insect prey. Often when they are searching for prey, they begin to sway their head horizontally until the snout contacts a larva or a pupa, upon which the blind snake will position its mouth over the prey, sometimes pinning it to the substrate.
The larvae is swallowed up until right behind the head, which is broken off by rubbing it against the substrate. Kley, ; Smith, et al. Eastern screech owls are known predators of Texas blind snakes. In fact, they are involved in an unusual, potentially commensalist relationship, in which live Texas blind snakes have been observed in the nests of screech owls.
In a study conducted by Gelbach and Baldridge , these owls brought live blind snakes to their nests. The snakes remained in the nest for days, living in the lower levels of the nest off of soft-bodied nest parasite larvae, until the owlets fledged and the snake was able to escape to the ground. It has been proposed that Texas blind snakes are able to survive the initial capture by the owl as it possesses a unique writhing mechanism that allows it to coil around the beak of the owl and remain relatively unharmed upon arriving back at the nest.
Gehlbach and Baldridge, Additionally, although raiding army ant colonies do not appear to prey on Texas blind snakes, they are a danger to blind snakes if they detect it amongst their ranks. The pheromones in Texas blind snake cloacal secretions protect them from attack. These pheromones also appear to repel ophiophagous snakes as well.
Predators range from large centipedes, snakes, and birds, to mammals such as moles, armadillos, skunks, and domestic cats. Ernst and Ernst, ; Watkins II, et al. As mentioned in the predation section, a commensal relationship has been proposed between Texas blind snakes and eastern screech owls. In this relationship, the owls experience reduced larval parasite populations in their nests, potentially increasing chick size, and the snakes are not harmed assuming they are able to return to the ground in a reasonable amount of time.
Watkins II, et al. There are no known positive impacts of Texas blind snakes on humans. Texas blind snakes are sometimes killed on highways or drown in suburban swimming pools. Domestic cats also prey on these snakes.
The most severe threats to this species are habitat alteration and the use of pesticides. Texas blind snakes are listed as Threatened and are protected in the state of Kansas. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate.
In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil.
Image processing: Dr. Jessie Maisano Publication Date: 12 Feb Leptotyphlops dulcis is a member of Leptotyphlopidae, a clade of small, slender, fossorial snakes commonly known as slender blindsnakes, threadsnakes or wormsnakes. All but one of the approximately 93 species of Leptotyphlopidae are contained within the genus Leptotyphlops.
Go to: main text of page main navigation local menu. Etymology The specific name is the Latin word duleis, meaning "sweet. Molecular phylogeny, classification, and biogeography of snakes of the Family Leptotyphlopidae Reptilia, Squamata. Zootaxa - get paper here Baird, S. Part 1.