Are flatworms Lophotrochozoa?
The flatworms are acoelomate organisms that include many free-living and parasitic forms. Most of the flatworms are classified in the superphylum Lophotrochozoa, which also includes the mollusks and annelids.
Do rotifers have trochophore larva?
In some mollusks (such as gastropods and bivalves), the trochophore develops into a second stage, the veliger (q.v.), before metamorphosing to adult form. Rotifers and the larvae (sometimes considered trochophores) of such invertebrates as phoronids and bryozoans are trochophore-like in appearance.
What are some common morphological features of the Lophotrochozoa?
The lophotrochozoans are triploblastic and possess an embryonic mesoderm sandwiched between the ectoderm and endoderm found in the diploblastic cnidarians. These phyla are also bilaterally symmetrical, meaning that a longitudinal section will divide them into right and left sides that are symmetrical.
What is special about Lophotrochozoa?
Of the three major bilaterian groups, Lophotrochozoa possesses the greatest morphological disparity as judged by the greatest diversity of distinct body plans. The lophotrochozoan hypothesis was first posited based on 18S nuclear ribosomal subunit gene DNA data by Halanych et al. (1995).
What do Lophotrochozoa and Ecdysozoa have in common?
Asexual reproduction is also common in this category. Every member of this group are triploblastic and shows bilateral symmetry. Both terrestrial and aquatic species are found in this group.
What are the two defining characteristics found in organisms that are grouped in the clade Lophotrochozoa?
The two defining characteristics of lophotrochozoans found in many members are (1) the presence of a horseshoeshaped crown of ciliated tentacles (lophophores), and (2) a minute, translucent top-shaped ciliated larvae (trochophores).
How do ecdysozoans grow?
Ecdysozoans are a morphologically heterogeneous group of animals which have a cuticle and grow by molting and include the arthropods and nematodes.
What 2 characteristics do many phyla in the Lophotrochozoa have in common?
What do veliger larvae eat?
phytoplankton
Free-living veliger larvae typically feed on phytoplankton; however, the larvae of some species are lecithotrophic (nourished by yolk from the egg that is retained within their bodies) and do not need to feed. In at least some cases, lecithotrophic veligers can also feed on phytoplankton.
Is Lophotrochozoa a clade of invertebrates?
Simultaneously with the ecdysozoan hypothesis, another major clade of invertebrates, Lophotrochozoa, has been proposed. This is an even more puzzling entity, where evolutionarily primitive Plathelminthes with two germ layers are united with such highly evolved three-layered animals as, for example, Mollusca.
What is the feeding apparatus of Lophotrochozoa?
Most organisms placed in the superphylum Lophotrochozoa possess either a lophophore feeding apparatus or a trochophore larvae (thus the contracted name, “lopho-trocho-zoa”). The lophophore is a feeding structure composed of a set of ciliated tentacles surrounding the mouth.
How many germ layers do Lophotrochozoa have?
Animals belonging to superphylum Lophotrochozoa are triploblastic (have three germ layers) and unlike the cnidarians, they possess an embryonic mesoderm sandwiched between the ectoderm and endoderm.
Is a trochophore a Lophotrochozoa?
A trochophore is a free-swimming larva characterized by two bands of cilia surrounding a top-like body. Some of the phyla classified as Lophotrochozoa may be missing one or both of these defining structures. Nevertheless their placement with the Lophotrochozoa is upheld when ribosomal RNA and other gene sequences are compared.