Larval and early post-larval morphology, growth, and behaviour of laboratory reared Lopholithodes foraminatus (brown box crab)

Abstract

The larval and post-larval behaviour, growth, colour, and morphology of the brown box crab (Lopholithodes foraminatus) are described for the first time based on laboratory reared animals. A detailed morphological description is provided for 4 zoeal stages, the glaucothoe, and the first crab instar. Selected morphological changes over the remainder of the first year of development are also described. Data are presented on larval growth at 11°C and on zoeal stage durations at approximately 8°C, 12°C and 16°C. While the 4 zoeal stages are planktotrophic, the glaucothoe does not feed; a life history character that has been termed ‘secondary lecithotrophy’. Growth of L. foraminatus larvae and post-larvae is generally similar to that of other North Pacific lithodids with planktotrophic zoeae. Zoeal stage durations decrease with increasing temperature. This relationship levels off at approximately 16°C, a higher temperature than in lithodid species from colder regions. Carapace morphology is suggested as a diagnostic character of larval and post-larval stages of Lopholithodes foraminatus. Secondary lecithotrophy may be widespread or even universal among lithodids and also occurs in pagurid hermit crabs. If the family Lithodidae is indeed nested within the Paguridae, as suggested by recent phylogenetic hypotheses based on molecular evidence, secondary lecithotrophy may be plesiomorphic in lithodids.

The enigma of reversed asymmetry in lithodid crabs: absence of evidence for heritability or induction of morphological handedness in Lopholithodes foraminatus

“…Capture and husbandry details and larval rearing methodologies are described in Duguid and Page (2009). If not otherwise specified, zoeae were reared either in 1 l glass beakers or 4 l plastic buckets at approximately 111C.…”

“…In the course of rearing work to describe the development of Lopholithodes foraminatus (Stimpson 1859) (brown box crab), I observed that a significant proportion of glaucothoe and early juvenile instars had a larger left claw (Duguid and Page 2009). I also captured a brooding female of L. foraminatus exhibiting reversed asymmetry of both the abdomen and chelae.…”

“…Chela size and morphology are antisymmetrical in American lobsters, Pearce 1986, 1989a, b), some alphaeid shrimp (Read and Govind 1997) and most fiddler crabs (Yamaguchi 1977); but are directionally asymmetrical in some families of predatory brachyuran crabs (Vermeij 1977;Ng and Tan 1985;Mariappan et al 2000), ghost crabs (Trott 1987) and at least one clade of fiddler crabs (Jones and George 1982). Directional asymmetry of the mandibles has been described in lobsters (Farmer 1974;Factor 1978) and in zoea larvae of several decapod groups (McLaughlin and Lemaitre 2001;Konishi 2007;Duguid and Page 2009). The hermit crab families Diogenidae, Parapaguridae, Coenobitidae, and Paguridae exhibit directional asymmetry not only of the chelae, but also of the abdomen; often accompanied by loss of the pleopods on one side (Richter and Scholtz 1994).…”

“…Small marginal plates occur only on the right, associated with the smaller lateral plates. This abdominal asymmetry first appears between the third and fifth crab instars (McLaughlin and Paul 2002;McLaughin et al 2003;Duguid and Page 2009). Analysis of the circulatory system of lithodids (genus Lopholithodes) has also revealed internal bilateral asymmetries, the most pronounced of which is a left-looping sternal artery (McGaw and Duff 2008).…”

“…To date, nothing is known about the inheritance of morphological handedness in directionally asymmetrical decapod taxa, although studies on other organisms suggest that reversal of directional asymmetry is normally caused by a heritable variation (Palmer 1996(Palmer , 2004. In the course of rearing work to describe the development of Lopholithodes foraminatus (Stimpson 1859) (brown box crab), I observed that a significant proportion of glaucothoe and early juvenile instars had a larger left claw (Duguid and Page 2009). I also captured a brooding female of L. foraminatus exhibiting reversed asymmetry of both the abdomen and chelae.…”