Question

Lancelet is
A. Hermania
B. Salpa
C. Branchiostoma
D. Doliolum

Answer 1

Hint: The lancelet is a benthic filter feeding chordates in order Amphioxiformes. Lancelet is also known as amphioxi and consists of 30-35 species of fish like chordates. They are modern representatives of the subphylum Cephalochordata.

Complete answer:
Lancelets are harvested commercially as food for humans and other domesticated animals. They provide evolutionary insight into the origin of vertebrates on Earth. Lancelet consists of various organs and organ systems which function in a primitive way. Gill-slits of the lancelets are used for feeding only, and not for the process of respiration. The circulatory system of the lancelet does not contain red blood cells or hemoglobin for transport of oxygen but transports food throughout the body.
Few species of lancelets are in genus Branchiostoma like B. floridae, B. lanceolatum, B. belcheri, etc. The Cephalochordata is seen in sister subphylum to the vertebrates, with which it is grouped together Notochord Data which is sister group to simple still Urochordata. Among the three living genera, Asymmetron is basal and placed in its own family. The two remaining genera, Branchiostoma and Epigonichthys diverged from each other about 36 million years ago. There are three families in order: Branchial Stomiiformes which are Epigonichthyidae, Asymmetronidae and Branchiostoma with genus Epigonichthys, Asymmetron and Branchiostoma respectively.

Hence, the correct option is C. Branchiostoma.

Note: Lancelets are distributed in shallow subtidal sand flats in temperate, subtropical and tropical areas of the world. Lancelets are gonochoric animals, i.e. having two sexes and reproduce with the help of external fertilization.