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Achatinella mustelina from different locations vary in size, shape, and color, but no specific patterns in these differences have been described. In general, adults range 19 — 24 mm in length, with an average length of The shells have a shiny finish and are usually brown with light bands that circle the suture convex, or they are white with transverse black or brown lines.
Shells of A. The shell is relatively high-spiraled and oblong to ovate with an aperture that is also oblong and ovate. The columella of A. A callus on the columella closes the umbilicus. The lip of the organism does not have any ridges, ribs, or folds.
Achatinella mustelina develops from an intrauterine embryo, and its growth in utero is thought to be logarithmic. Young are born live and are approximately 4. The snail grows at a relatively slow rate of 2 mm per year, and over the course of four to five years, it will only grow to be five times its birth length. Growth in A. A unique characteristic of development in A. Hadfield and Mountain, ; Hadfield, et al. Achatinella mustelina is hermaphroditic, and may self-fertilize.
Achatinella mustelina has a lengthy gestation period and gives birth to large, live young that mature late and have a low fecundity. Although reproductive maturity occurs after the maximum size is reached, reproductive maturity may be dependent on age, not size. Reported age at maturity varies, ranging from 3 to 6.
Similarly, reports of fecundity vary, but rates as low as 0. Little information about reproductive behavior in Achatinella mustelina is known, but this species is hermaphroditic and thought to breed year-round.
Some species of the genus Partulina , sister to Achatinellidae , are thought to self-fertilize, so A. Partulina redfieldii can reproduce even in long-term absence of mates. The mechanism of this form of reproduction is not clear, however. Possibilities include parthenogenesis and long-term sperm storage, in addition to self-fertilization. Genetic evidence suggests interchiral mating takes place for A. Other terrestrial gastropods with high-spired shells like A.
One snail inserts its penis in to the other and releases spermatophores. Embryos are intrauterine, and no more than two large embryos are contained in the uterus; usually there is only one. The large size of newborn A.
Hadfield and Mountain, ; Hadfield, ; Hadfield, et al. Although the literature does not include specific information about parental investment in Achatinella mustelina , in general, terrestrial gastropods do not provide parental care after birth. The most common form of parental investment for terrestrial gastropods comes in the form of calcium carbonate and other nutrients given to the developing egg. Baur, Achatinella mustelina has a relatively long lifespan compared to other terrestrial gastropods.
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