Other formats

    Adobe Portable Document Format file (facsimile images)   TEI XML file   ePub eBook file  


    mail icontwitter iconBlogspot iconrss icon

Zoology Publications from Victoria University of Wellington—Nos. 78, 79 and 80

Unabbreviated development

Unabbreviated development

Species with four or more planktonic zoeal instars in their life history.

Key to zoeal stage
A. Eyes sessile zoea 1
Eyes stalked B
early stage
B. Uropods not freed from telson (Fig. 2F) zoea 2
Uropods freed from telson C
C. Uropod endopod rudimentary (Fig. 2E) zoea 3
Uropod endopod and exopod developed D
D. Pleopods absent or rudimentary (Fig. 2D) zoea 4+
late stage
Pleopods setose and functional postlarvae

Early and late stages are arbitrarily defined. The terms are useful when referring to larvae in which the number of instars is variable or unknown, or when more than one instar is referred to. Early larvae are those in which there are no pleopod buds, and usually refers to zoeae 1-3. Late larvae are those in which all the appendages are present and well formed, and the pleopod buds are large but not yet setose. Intermediate classification into mid-stage larvae is only necessary when page 3there are a large number of instars and the degree of morphological change between them is small. Mid-stage larvae are zoea 4+ larvae in which pleopod buds are absent or small.