Arenicola brasiliensis.doc

7/22/2019 Arenicola brasiliensis.doc

1/4

Arenicola brasiliensis (Nonato, 1958) Eukarya

Animalia

Annelida

Languages: English

Overview

Comprehensive Description

The lugwormArenicola brasiliensis (which for many years was not distinguished from the

similarA. cristata) is a polychaete annelid worm in the family Arenicolidae. It is widelydistributed, especially in warmer parts of the word. This worm digs a J- or L-shaped burrow and

orients itself so that its posterior (rear) end is close to the surface. The anterior (head) end, which

is kept well below the surface at the bottom of the J, ingests sand, creating a closed, funnel-shaped depression in the sand surface above the head. The worm swallows sand and mud, which

adhere to mucus secreted on the everted (extended out of its body) proboscis. When the

proboscis is inverted, the material sticking to it is pulled into the digestive system. Organicmatter ingested with the sand is rapidly digested and the processed sand is periodically defecated

at the surface near the tail end of the burrow in a distinctive long, coiled casting (the related A.

cristata deposits fecal wastes in sandy sheets). The branched gills receive circulating blood,

which contains hemoglobin. Gas exchange in the burrow is facilitated by pistonlike movementsof the body, which stir the water and irrigate the burrow. Lugworms may reach densities as high

as 50 per square meter and play an important role in turnover of organic matter in mudflats.

(Morris et al. 1980; Kozloff 1993)

Author(s): Shapiro, Leo

Rights holder(s): Shapiro, Leo

Comment (0)

Description

Lookalikes

Arenicola brasiliensis was long confused withA. cristata, which tends to live in quieter, muddier

places.Arenicola brasiliensis extrudes earthworm-like coiled castings outside its burrow, whileA. cristata castings leave a formless film or heap. The egg mass ofArenicola cristata has the

appearance of a gelatinous streamer, while the eggs ofArenicola brasiliensis are firm and "egg-

shaped". (Gosner 1978). The overall color ofA. cristata tends to be greenish black, while the lessrobustA. brasiliensis is pinkish tan (Pollock 1998). Pollock suggests that A. brasiliensis might

simply be a smaller growth form ofA. cristatus (Pollack 1998). DNA sequencing (e.g., of the

cytochrome oxidase I gene, a portion of which is widely used as a "bar code" for animals) of
http://eolspecies.lifedesks.org/pages/36364http://eolspecies.lifedesks.org/pages/14003http://eolspecies.lifedesks.org/pages/15868http://eolspecies.lifedesks.org/pages/21246/?lang=en#taxonpage-languagehttp://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://creativecommons.org/licenses/by-nc-sa/3.0/http://eolspecies.lifedesks.org/pages/14003http://eolspecies.lifedesks.org/pages/15868http://eolspecies.lifedesks.org/pages/21246/?lang=en#taxonpage-languagehttp://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/pages/36364


2/4

multiple representatives of these two putative species might clarify this question, but this has

apparently not been done.



Comment (0)

Morphology

Arenicola lugworms are robust annelid worms, thickest in the front half, tapering toward the

head and (more gradually) toward the rear. A 2 cm worm is about 9 mm wide and divided into 3

regions. The trunk has weak parapodia bearing bundles of setae and (starting roughly 1/3 of theway back) a tuft of gills on each side. The tail region lacks setae and parapodia. The small,

contractile head lacks appendages but has an eversible proboscis armed with papillae. (Gosner

1978)

Arenicola brasiliensis may grow to 175 mm, with 17 segments bearing setae. It has 11 pairs ofgills, on segments 7 to 17. (Morris et al. 1980)



Comment (0)

Ecology

Ecology

Arenicola brasiliensis burrows in sand and mud in the low intertidal zone in bays (Morris et al.1980).



Comment (0)

Distribution

The polychaete lugwormArenicola brasiliensis is widely distributed, especially in warmer parts

of the word (although it may be abundant in temperate regions as well, such as certain localitiesin San Francisco Bay, California, U.S.A.) (Kozloff 1993).

Arenicola brasiliensis is found along both coasts of North & South America, as well as in

Hawaii, Japan, and Australia; it is broadly cosmopolitan in warmer seas (Morris et al. 1980).
http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://creativecommons.org/licenses/by-nc-sa/3.0/http://creativecommons.org/licenses/by-nc-sa/3.0/http://creativecommons.org/licenses/by-nc-sa/3.0/http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175


3/4

According to Gosner (1978), on the Atlantic coast of North AmericaA. brasiliensis is known

only along the south shore of Cape Cod, but its range also includes Brazil and parts of the Pacific

Ocean.


Rights holder(s): Shapiro, Leo Comment (0)

Trophic Strategy

Arenicola lugworms feed on fine particles carried on currents pumped through their burrows

(Gosner 1978).



Comment (0)

Reproduction

Arenicola brasiliensis has separate males and females. After gametes (sperm and eggs) mature in

the body cavity, they are discharged through six pairs of tubular ducts. Mature eggs are about

150 microns in diameter. In a study in Japan, spawning occured from July to September. Eggrelease may be stimulated by the presence of sperm in the water. Eggs are shed in the burrow,

where fertilization occurs. A few hours after fertilization, the eggs are embedded in a firm jelly

mass, just 2 to 5 cm in diameter but up to 15 cm long, extruded to the sand surface but remaining

firmly rooted in the burrow by a tenacious stalk. Hatching occurs several days after fertilizationand shortly thereafter the jelly mass breaks down, releasing the larvae. Larvae swim for a short

time, then settle and begin to burrow. (Morris et al. 1980)



Comment (0)

Evolution and Systematics

Systematics and Taxonomy

Arenicola brasiliensismay be referred to in some older literature by the junior synonym

A.

caroledna and has not always been distinguished fromA. cristata (Morris et al. 1980).


Rights holder(s): Shapiro, Leo Comment (0)

References
http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://creativecommons.org/licenses/by-nc-sa/3.0/http://creativecommons.org/licenses/by-nc-sa/3.0/http://creativecommons.org/licenses/by-nc-sa/3.0/http://creativecommons.org/licenses/by-nc-sa/3.0/http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/user/17http://eolspecies.lifedesks.org/node/1175


4/4

Brusca, R. C., & Brusca G. J.(2003). Invertebrates, 2nd edition. Sunderland, Massachusetts:

Sinauer.

Gosner, K. L. (1978). A Field Guide to the Atlantic Seashore. Boston: Houghton Mifflin.Kozloff, E. N. (1993). Seashore Life of the Northern Pacific Coast, 3rd printing (with

corrections). Seattle: University of Washington Press.

Morris, R. H.,Abbott D. P., &Haderlie E. C. (1980). Intertidal invertebrates of California. PaloAlto, California: Stanford University Press.

Pollock, L. W. (1998). A Practical Guide to the Marine Animals of Northeastern North America.

New Brunswick, New Jersey: Rutgers University Press.
http://eolspecies.lifedesks.org/biblio/author/1146http://eolspecies.lifedesks.org/biblio/author/1146http://eolspecies.lifedesks.org/biblio/author/1147http://eolspecies.lifedesks.org/biblio/author/1147http://eolspecies.lifedesks.org/biblio/view/931http://eolspecies.lifedesks.org/biblio/view/931http://eolspecies.lifedesks.org/biblio/author/832http://eolspecies.lifedesks.org/biblio/view/640http://eolspecies.lifedesks.org/biblio/view/640http://eolspecies.lifedesks.org/biblio/author/1365http://eolspecies.lifedesks.org/biblio/view/1123http://eolspecies.lifedesks.org/biblio/view/1123http://eolspecies.lifedesks.org/biblio/view/1123http://eolspecies.lifedesks.org/biblio/author/1426http://eolspecies.lifedesks.org/biblio/author/1427http://eolspecies.lifedesks.org/biblio/author/1427http://eolspecies.lifedesks.org/biblio/author/1428http://eolspecies.lifedesks.org/biblio/author/1428http://eolspecies.lifedesks.org/biblio/view/1176http://eolspecies.lifedesks.org/biblio/author/831http://eolspecies.lifedesks.org/biblio/view/639http://eolspecies.lifedesks.org/biblio/author/1146http://eolspecies.lifedesks.org/biblio/author/1147http://eolspecies.lifedesks.org/biblio/view/931http://eolspecies.lifedesks.org/biblio/author/832http://eolspecies.lifedesks.org/biblio/view/640http://eolspecies.lifedesks.org/biblio/author/1365http://eolspecies.lifedesks.org/biblio/view/1123http://eolspecies.lifedesks.org/biblio/view/1123http://eolspecies.lifedesks.org/biblio/author/1426http://eolspecies.lifedesks.org/biblio/author/1427http://eolspecies.lifedesks.org/biblio/author/1428http://eolspecies.lifedesks.org/biblio/view/1176http://eolspecies.lifedesks.org/biblio/author/831http://eolspecies.lifedesks.org/biblio/view/639

Documents

Arenicola brasiliensis.doc