Effect of temperature on growth of the intertidal purple snail Plicopurpura pansa (Gould 1853) under laboratory conditions

Abstract

To determine the optimum temperature for growth of the endangered intertidal purple snail Plicopurpura pansa (Gould 1853) (Prosobranchia, Muricidae), 731 adult specimens were reared in the laboratory on squid for 86 days at temperatures ranging from 20 to 32 1C. The snails showed extremely slow growth, if at all. Males and females raised at 26 1C grew the fastest, an average of 0.85 and 0.43 mm respectively. No statistically signi¢cant di¡erences were observed at other temperatures or between males and females. The best temperature for growth for the intertidal purple snail appears to be in the range between 26 and 30 1C.

Growth, settlement and survival ofDicathais orbita(Neogastropoda, Mollusca) larvae in response to temperature, diet and settlement cues

“…) and ~280 μm (Naegel et al . ) respectively. Fifteen dph C. concholepas was ~300 μm and had increased to 520 μm after 20 days; by 120 days the larvae had attained a shell length of ~1600 μm (Di Salvo ).…”

“…P. pansa grew to ~470 μm in the first 28 days and had a shell length of more than 1000 μm after 105 dph (Naegel et al . ). This indicates that there could be much potential for further growth of D. orbita larvae if they can be maintained in culture for longer intervals of time.…”

“…Naegel et al . () found that P. pansa settled in response to ~25 mM KCl. Overall, whereas lower concentrations of KCl (20 mM) can be used to artificially induce settlement of Muricidae larvae, it would be preferable to identify natural settlement cues.…”

“…The experiment was run with batches of larvae at different stages of development: the day of hatching (day 0), 10 days post hatching (dph) (day 10), 20 dph (day 20) and at 30 dph (day 30). The number of larvae responding to settlement cues in each batch was monitored for 10 min h −1 for the first 7 h and again at 18, 24, 48, 36, 60 and 72 h. Settlement observations focused on pre‐metamorphic cues, such as sinking and creeping behaviour, which have been noted in other species of gastropod larvae prior to metamorphosis (Di Salvo ; Davis ; Naegel, Rodríguez‐Astudillo, Hernández‐Ceballos & Cáceres‐Martínez ). Five settlement cues were trialled in this study: KCl, live and dead (carrion) prey ( Xenostrobus pulex Lamarck), an algal biofilm of Ulvella lens Crouan & Crouan and the mucus of adult conspecifics.…”

Laboratory spawning, larval development and metamorphosis of the marine snailNassarius reticulatus(L.) (Caenogastropoda, Nassariidae)

“…In fact, most studies on larval stages of gastropod molluscs are based on collections in the field or observations of the first larval phases, and they do not permit to follow their complete development. Taking into account also the possible interest of N. reticulatus for aquacultural practices (Nasution and Roberts, 2004), it would be useful to identify a correct feeding programme and to describe its complete development in the laboratory, from hatching to the adult, as has been obtained for a few commercially interesting gastropod molluscs (e.g., Manzano et al, 1998;Naegel et al, 2003;Nasution and Roberts, 2004).…”