Artificial reproduction protocol, from spawning to metamorphosis, through noninvasive methods in Patella caerulea Linnaeus, 1758

Abstract

Controlled reproduction is a requirement for developing effective mollusc cultivation for commercial or restoration purposes. In this study, a protocol for spawning induction using noninvasive methods in limpets was developed, using the common Mediterranean species, Patella caerulea Linnaeus, 1758. Six nonlethal spawning induction treatments were tested: three chemical (two concentrations of H 2 O 2 and KCl) and three physical (bubbling, warm and cold thermal shock). All treatments, except thermal shocks, induced the spawning of fertile gametes. Bubbling resulted the best treatment in providing spawning response, being the easiest and least invasive method tested. After eggs fertilization, larval development was followed until metamorphosis, testing fed and unfed conditions. Settlement took place after 7 days. The developed protocol represents a benchmark for further application to other limpets, for aquaculture or repopulation. K E Y W O R D Sartificial reproduction, limpet aquaculture, Patella caerulea, spawning induction

Recruitment of the limpetPatella ulyssiponensisand its relationship with crustose coralline algae: patterns of juvenile distribution and larval settlement

“…presence of a conspecific adult cue for P. caerulea (Wanninger et al ., 1999; Ferranti et al ., 2018) and proximity to the air-water interface for P. ferruginea (Guallart et al ., 2017). Experimental investigation in vitro regarding settlement is hampered by the fact that the actual quantity of settlers and/or metamorphosed juveniles produced in laboratory studies was either very limited (Smith, 1935; Wanninger et al ., 1999; Guallart et al ., 2017) or not quantified (Dodd, 1957; Ferranti et al ., 2018). Additionally, consistent evidence has been recently gathered concerning the need to supply settlers with a food suitable for their benthic mode of feeding (an algal film to be scraped by the radulae, i.e.…”

“…This is partly because settlers of these species (only detectable by microscopic examination), have rarely been found in nature (but see Bowman, 1985; Gardner, 1986; McGrath & Foley, 2005). Rearing of larval patellids to settlement and metamorphosis is also very rare (but see Smith, 1935; Dodd, 1957; Wanninger et al ., 1999; Ferranti et al ., 2018). Laboratory assays with Patella embryos and larvae are often referred to as methodologically difficult (Dodd, 1957; Smaldon & Duffus, 1984; Espinosa et al ., 2010; Pérez et al ., 2016), which has probably impaired the progress of laboratory settlement studies.…”

Effects of ocean warming on larval development of Patella ordinaria from the Canary Islands

“…As limpets do not show external sexual dimorphism, all individuals were exposed to spawning induction by different techniques reported in the bibliography, along with newly tested approaches. The chosen techniques consisted of strong continuous air bubbling and/or injecting KCl, a compound used in other invertebrates to induce spawning (Corpuz, 1981;Ferranti et al, 2018;Kay and Emlet, 2002).…”

“…For the bubbling method, seven individuals were deposited in seven 100 ml sterile beakers in FSW. Seawater was vigorously bubbled for 2 h using standard Eheim aquarium oxygenators positioned at the bottom of each beaker (Kay and Emlet, 2002;Ferranti et al, 2018). The KCl technique was applied to seven individuals by injecting 1.5ml of KCl (0.1 M) through the mantle.…”

“…Before fecundation, sperm mobility and eggs state were checked. No eggs were exposed to alkalinization conditions, despite such recommendations in the literature (Ferranti et al, 2018).…”