Figure 4 in New insights on the external features of egg capsules and embryo development in the squid Loligo vulgaris

Figure 4. Comparison of the chronological appearance of selected organs in seven loliginid species from previous studies (Arnold 1965; Segawa et al. 1988; Baeg et al. 1992; Guerra et al. 2001; Barón 2002) and the present study. The embryonic stages of Arnold were used because these stages were employed in previous comparisons (Guerra et al. 2001). Abbreviations: EC, eye vesicle closed; EI, eye vesicle invagination begins; FF, funnel formation begins; HO, Hoyle's organ appears; IS, ink sack appears; PED, fully establish eyelid; PL, primary lip; PS, primordia of suckers appear; PSG, primordia of shell gland appear; RP, retinal pigmentation begins; SGC, shell gland closed; ST, statocyst first presence; and VCH, ventral mantle chromatophores appear.