Tubeworm species that broadcast gametes are considered here, while SPECIES THAT BROOD OUTSIDE OF TUBE, SPECIES THAT BROOD INSIDE OF TUBE, and SPECIES THAT ARE POECILOGONOUS are considered in other sections. There is also a general section on LARVAE. Photograph courtesy Kevin Lee, Fullerton, California diverKevin.

Parchment worms Chaetopterus sp. spawning. At
least one of the worms is a male, emitting sperm 1X

West-coast tubeworms Dodecaceria fewksii inhabit calcareous tubes and live in large, sprawling colonies.  Interestingly, the members of a colony consist of a single sex, likely a result of of cloning via autotomy and then regeneration of parts.  The pattern, described earlier for a European species Dodecaceria caulleryi, is thought by the authors perhaps also to apply to D. fewksii.  In this unique pattern, a portion of the middle part of the body separates into 2 individual segments plus the original head and tail.  Each of the 2 segments sprouts 2 buds, which grow to small adult-stage, then separate.  The segments repeat this process one more time, then die.  All 4 buds become adults of the same sex as the original worm.  Additionally, the head and tail ends regenerate. Each  of these components has the potential to drift or swim off to form a new colony. The process was originally termed schizometamery but, possibly for reason of its rarity, the discriptor seems not to be in current use.  The present studies on D. fewksii from Vancouver Island, British Columbia reveal that individuals undergo sexual reproduction, with release of gametes, and development to a trochophore larval stage and to early segmentation (see drawings below).  Settlement and metamorphosis are not observed by the authors in their laboratory cultures.  A follow-up study would be justified to check if D. fewksii also reproduces asexually as described for D. caulleryi above. Berkeley & Berkeley 1954 J Fish Res Bd Can 11: 326.

NOTE Dehorne 1933 Bull Biol France Belgique 67: 298

A group of black-tentacled cirratulids Dodecaceria fewksii
partly overgrown by a colonial tunicate. Several solitary
tunicates Styela montereyensis appear to be gradually losing
out to the colonial species in the competition for space 0.5X

Intertidal tubeworms Serpula columbiana in San Juan Islands, Washington are reproductive in spring and summer, and freely spawn their eggs and sperm.  Spawning can be induced by disturbance, such as by blowing (with compressed air) the worm out of its tube into a fingerbowl.  The embryos hatch as trochophore larvae within a day of fertilisation and can be raised on cultured flagellates Dunaliella.  A single brilliant red eyespot or ocellus is present at this time.  By 26d at 12^oC segmentation commences, 2 eyespots are prominent, and the larva is known as a metatrochophore. At 30d of age, setae appear on the nectochaete larva, and it settles to the bottom and begins crawling about. Metamorphosis occurs at 50d and the little worm now has a well-defined head with tentacle buds.  The larvae are photopositive up until about 25d, after which they become strongly photonegative.  Even the newly hatched trochophores swim upwards to the light but, as they lack eyespots, it is assumed that they are responding negatively to gravity.  The benthic nectochaete larvae appear to be indifferent to light, but at metamorphosis they orient the aperture of their tubes away from the light. The authors suggest that the eyespots in the swimming larvae may function in daily (diel) migrations - towards the surface at night and away during the day – possibly to avoid being eaten by visual predators.  These ideas, however, are based on laboratory observations, and it is not known whether the larvae behave in this way in the field.  Young & Chia 1982 Biol Bull 162: 457.

Several serpulid worms Serpula columbiana.
No research appears to have been done on the
variable colours in this species 0.7X

Developmental stages highlighted in black in the above account are shown in the photos below:

Sexes are separate in the southern California reef-building tube worm Phragmatopoma californica and gametes are freely spawned.  After several weeks or months feeding in the plankton, the larvae settle, often gregariously with adults. 

Experiments at the Scripps Institution of Oceanography, La Jolla, California show that several free fatty acids (FFA) present in the sand/organic-cement matrix of adut tubes actively stimulate the larvae to settle and metamorphose. Response of the larvae is dosage-dependent, as shown in the accompanying histogram for a known inducer fatty acid, palmitoleic acid (16:1).  Note that settlement is less for another fatty acid, eicosapentaenoic acid (20:5), and larvae develop abnormally in high concentrations of this substance. In a follow-up study, the research group determines that settlement of Phragmatopoma larvae is enhanced in higher current flows.  This is because the larvae tumble along the bottom and are brought into more intimate contact with inducer chemicals in the sand.  In slower flows, the larvae swim along in the water column and make less contact with the sand. This behaviour of larvae in different flow conditions may play an important role in their recruitment. Pawlik 1986 Mar Biol 91: 59; Pawlik et al 1991 Science 251: 421; Pawlik & Faulkner 1986 J Exp Mar Biol Ecol 102: 301; for a comparison of settling characteristics of P. californica with those of a European counterpart Sabellaria alveolata see Pawlik 1988 J Mar Biol Ass UK 68: 101. Photograph courtesy Lovell & Libby Langstroth, California and calphotos.edu.

NOTE  the researchers employ a racetrack-design flume tank with a 6-m straightaway containing an array of experimental sediments on its bottom.  Treatments include sands containing different concentrations of FFAs previously shown to be inductive (e.g., palmitoleic acid, 16:1) and non-inductive (e.g., palmitic acid, 16:0), sand from tubes of adult worms, and appropriate controls.  Larval-mimicking polystyrene spheres are also employed to monitor flow characteristics of the design


Part of a colony of tubeworms Phragmatopoma
californica. Note the sand-grain type of
construction of the tubes 4X

A study on reproduction in the small, tube-dwelling polychaete Owenia collaris at the Oregon Institute of Marine Biology and Friday Harbor Laboratories, Washington provides information on early development and metamorphosis for Family Oweniidae.  Fertilisation after broadcast spawning leads within 12-24h to a free-swimming gastrula and then to a feeding mitraria larva within 48h (10-13^oC, see photographs on Left). Metamorphic competence is attained after about 4wk in culture. 

By 3d after metamorphosis the juveniles, now about 1.2mm in length, are gathering sand grains to make their tubes (see photograph on Right). The authors note several unexpected features of development in common with deuterostomes, including the blastopore forming the anus, in contrast to it forming the mouth in other protostomes, suggesting that protostomial development may be more plastic than once thought.  Smart & Dassow 2009 Biol Bull 217: 253. Photographs courtesy the authors.

NOTE  larvae are fed in laboratory culture on 1:2 mixture of Rhodomenas lens  and Isochrysis galbana