Worldwide patterns in mode of development in calyptraeid gastropods

Abstract

The mode of development in marine invertebrates is believed to have consequences for dispersal, gene flow, geographic range, and speciation and extinction rates. The factors responsible for among-species differences in mode of development are not well understood and patterns of variation in mode of development have not been documented for many groups. I present a compiled data set of developmental characters for 78 species of calyptraeid gastropods: 53 Crepidula, 9 Calyptraea, 11 Crucibulum and 5 other species. Analysis of this data set shows that egg-and hatching-size distributions are strongly positively skewed. As expected, egg size correlates with hatching size and time to hatching in species without nurse eggs. Egg size is not significantly different between species with planktotrophic development and species with direct development with nurse eggs. Hatching size of direct developers with and without nurse eggs do not differ. Developmental characters do not vary with adult body size among species. There are strong latitudinal effects in mode of development, the frequency of planktotrophic species decreases with increasing latitude while the proportion of direct developers increases. There is also a striking latitudinal pattern in the occurrence of nurse eggs; almost all species with nurse eggs occur in the southern hemisphere. These latitudinal patterns do not appear to be explained by sea surface temperature. Comparisons with other gastropods for which similar compilations are available show a striking difference between heterobranchs (opisthobranchs and pulmonates) and caenogastropods in developmental characteristics.KEY WORDS: Larvae · Invertebrate development · Crepidula · Crucibulum · Calyptraea Resale or republication not permitted without written consent of the publisher

Brooding and Species Diversity in the Southern Ocean: Selection for Brooders or Speciation within Brooding Clades?

“…That is, nonpelagic development in the Southern Ocean might not refl ect adaptation scattered among several clades, as it does elsewhere (e.g., Byrne et al, 2003;Collin, 2003), but rather, it may occur mainly in relatively few clades in which species proliferated. Moreover, some of these species-rich, brooding clades could contribute substantially to the unexpected high species diversity found in the Southern Ocean (Brandt et al, 2007a(Brandt et al, , 2007bRogers, 2007).…”

Effect of oxygen conditions on intracapsular development in two calyptraeid species with different modes of larval development

“…We used 2 marine gastropod species of the family Calyptraeidae; the indirect developer Crepidula fornicata and the direct developer C. coquimbensis, to assess O 2 conditions during encapsulated development, the factors determining O 2 conditions, and the consequences on embryo survival. The calyptraeids are good subjects for these studies because females of every species encapsulate and brood their embryos at least up to the veliger stage (Hoagland 1986, Collin 2003. If O 2 availability for embryos constrains the duration of protection, it is expected that C. coquimbensis which exhibits direct development and extended protection (i.e.…”

Hatching, Growth and Feed Preference of Hatchlings of<i> Volagalea cochlidium</i> (Linnaeus, 1758)

“…This is the case in H ternatanus, H tuba, B undulatum (Lu et al, 2009;Tang et al, 2012), where as in B spirata, B areolata, C ramosus the development is intra capsular up to free swimming veliger stage and metamorphosis is completed externally (Shanmugaraj et al, 1994;Sreejaya et al, 2004;Chaitanawisuti, and Kritsanapuntu, 1997;Nugranad and Kerdpoom, 1995). Planktotrophic and direct development are the two types of development in most gastropods and there exists a strong latitudinal pattern in direct development (Natarajan, 1957;Wilson, 1985;Collin, 2003). Nurse eggs were absent in H pugilinus although reported in several other gastropods with intra capsular development (Natarajan, 1957;Jagadis et al, 2012).…”

“…In the spotted babylon Babylonia areolata and the spiral babylon B spirata, the hatchlings are planktonic and become benthic after metamorphosis (Chaitanawisuti and Kritsanapuntu, 1997;Sreejaya et al, 2004); in other species metamorphosis occurs prior to hatching (Collin, 2003., Gallardo and Penchaszadeh 2001, Morton 1986a, Wilson, 1985, Hamada1974, Xu et al, 2006. Understanding feeding, feed requirements and the impact of diets on growth and survival will facilitate the culture of whelks.…”