Acorn worm - Wikipedia
Acorn worms are dioecious, having separate biological sexes, although at least some species are also capable of asexual reproduction in the form of fragmentation. [25] They have paired gonads , which lie close to the pharynx and release the gametes through a small pore near to the gill slits.
Acorn worm - New World Encyclopedia
Acorn worms have separate genders and reproduce sexually, releasing eggs and sperm into the water for external fertilization. In some, eggs develop into free-swimming larvae that look very similar to echinoderm larvae.
Acorn worms in a nutshell | Nature
2015年11月18日 · Enteropneusts, better known as acorn worms, use internal gill slits in the pharynx region of their trunk to move water through their mouth to obtain oxygen and, in some species, for filter...
Acorn Worm Facts and the Regeneration of Human Body Parts
At least some species of acorn worms can reproduce asexually when bits of the worm's trunk break off and grow into new animals. The larvae of acorn worms closely resemble those of the phylum Echinodermata, which contains starfish, sea urchins, and sea cucumbers.
Acorn worm | Marine Invertebrate, Tube-Dwelling, Filter Feeder
Acorn worms have separate sexes. Paired gonads are located next to the gills, which lie in the “trunk” of the animal, behind the collar. Females of some species lay a few large eggs with much yolk; others lay many small eggs with little yolk.
Hemichordates: Hemichordata - Encyclopedia.com
BEHAVIOR AND REPRODUCTION. Acorn worms live alone sheltered in their burrows, under rocks, or in thick tangles of plants. The burrowing species use their snout for digging. They line the U-shaped burrows with mucus to strengthen the walls.
An Anatomical Description of a Miniaturized Acorn Worm ... - PLOS
2012年11月7日 · Here we report the first meiofaunal, interstitial adult acorn worm and provide a detailed description of its anatomy and possible reproduction mode. We further test its phylogenetic position using DNA sequence data and standard phylogenetic analyses.
Hemichordates: Hemichordata - Behavior And Reproduction
Burrowing acorn worms sometimes stretch their snout and collar out of the tunnel, but they spend most of their time underground. Some hemichordates gather their meals by stirring up currents with the hairlike fibers on their body and drawing in nutrients from the water.
Morphological characterization of the asexual reproduction in the acorn ...
2010年8月27日 · The acorn worm Balanoglossus simodensis reproduces asexually by fragmentation and subsequent regeneration from the body fragments. We examined the morphogenesis of its asexual reproduction.
Hemichordata World Database - WoRMS - World Register of …
2 天之前 · Hemichordata is a unique phylum of marine invertebrates found in a wide range of depths and habitats. Two distinctly different body plans exist in this phylum: the large, solitary acorn worms (Class Enteropneusta), and the filter-feeding colonies of the class Pterobranchia.