The Morro shoulderband snail is very much a coastal organism. Its primary habitat consists of coastal dune, coastal dune scrub, and maritime chaparral plant communities that are mostly in back dune and stabilized dune systems, but always on Baywood fine sands soil type. They have also been found in numerous suburban landscaped habitats, fields, and often in high concentrations within non-native plants, such as veldt grass (Ehrharta calycina) and ice plant (Carpobrotus edulis).  

Not much is known about the Morro shoulderband snail’s diet. However, inferences have been made about its food preferences based off studies of closely related species within the Helminthoglypta  genus that occupy similar habitats. From these studies, we surmise that Morro shoulderband snails typically eat dead plant material and the fungus associated with detritus.  

Morro shoulderband snails spend most of the year in aestivation, and like other Helminthoglypta species, Morro shoulderband snails are active almost exclusively during the rainy season, which in coastal San Luis Obispo County is between October and April. After the first soaking rains of the rainy season or when barometric pressure begins to drop prior to rainfall, Morro shoulderband snails emerge from aestivation to find food and reproduce.  They are most active when the humidity is highest in the early evening, night, and early morning hours. Terrestrial gastropods like the Morro shoulderband snail don’t move very much and usually only to find food or reproduce. They use their sense of smell to find food sources. As conditions become drier, the activity of Morro shoulderband snails begins to decrease and they seek out suitable places to aestivate. Morro shoulderband snails select opportunistic locations for aestivation which can vary from native and non-native plants, accumulations of leaf litter and grass, dense clumps of native and non-native grass and young ice plant (Carpobrotus spp.), cactus (Opuntia spp.), and anthropogenic features and debris (stockpiled construction materials, wood, cement, plastic), and lower outer branches of shrubs. Helminthoglypta species can survive aestivation up to 170 days, and lose as much as 40 percent of their body weight. Smaller snails do not survive extended dry period probably due to their thinner shells and higher surface to volume ratio. Snails can regan as much as 50 percent of their lost body weight during the first 24 hours following aestivation. 

Like other species in the genus Helminthoglypta, Morro shoulderband snails have helix-shaped or spiral shells that are reddish brown to chestnut in color. Their shells have five to six whorls and a single, narrow dark spiral band on the “shoulder” with thin light yellowish margins above and below. Adult shell dimensions range from 18 to 29 mm (0.7 to 1.1 in.) in diameter and from 14 to 25 mm (0.6 to 1.0 in.) in height. 

Many species within the Helminthoglypta genus occur in the Mediterranean climate regions of California and have adapted to changing environmental conditions by having a two-part life cycle. While feeding, reproduction, and most individual growth occurs during the rainy season, the Morro shoulderband snail spends the majority of the year can be spent in aestivation (a period of prolonged dormancy) to survive the drier portions of the year. During the dry months, the Morro shoulderband snail develops an epiphragm, a durable seal of dried mucous, over the opening of its shell to prevent it from drying out. Once the rains begin in late fall and winter, the epiphragm is shed and the snail emerges to feed and seek out mates. 

As with reproduction, most growth among Helminthoglypta species occurs during the rainy season when moisture conditions are suitable for feeding activity. For Helminthoglypta arrosa, a similar species to Morro shoulderband snail, maturity is reached in 3 to 3.75 years living in coastal scrub and estimated longevity is 6 to 10 years. It is possible that these maturation and longevity patterns for the Morro shoulderband snail could be similar. 

Many aspects of reproduction and reproductive behavior of Morro shoulderband snail may be similar to other related Helminthoglypta species. Morro shoulderband snails become sexually mature at about 3-4 years of age, indicated by a noticeable outward flair of the edge of the shell opening. Like most terrestrial gastropods, species in this genus are hermaphroditic (they have both male and female reproductive organs) and lay eggs. After the first soaking rains of the wet season, Morro shoulderband snails emerge from aestivation and begin mating at night and during overcast days. Eggs are deposited in shallow holes in the soil below the leaf litter and hatch approximately 6 months later. Species of Helminthoglypta can reproduce multiple times a year. 

The Chorro shoulderband snail (Helminthoglypta morroensis) is another banded dune snail within the Helminthoglypta genus. At the time of listing in 1994, it was believed that Chorro shoulderband snail was extinct. However, within a few years of listing, Chorro shoulderband snail was rediscovered near the northern limit of Morro Bay. Since the time of listing, living Chorro shoulderband snail individuals have been documented at other locations from northern Morro Bay south and inland through the City of San Luis Obispo. The Chorro shoulderband snail has a range extending from the coastal community of Cayucos through the Los Osos Valley to the community of Edna, east of the City of San Luis Obispo.