Streblospio benedicti   Webster,  1879 (Marine Worm)
Organism information awaits expert curation
Class: Polychaeta

Image copyrights: David Samuel Johnson

Size: 6 mm

Color: Individuals are typically reddish-brown and slightly transluscent, with dark green-brown gill bands.

Streblospio benedicti is a small, segmented, tube-dwelling infaunal polychaete. The head is conspicuous, conical in shape, with four eyes, two banded gills and a pair of coiling, tentacle-like feeding palps. Each body segment is equipped with paired, paddle-like setose parapodia that are less robust than in many polychaetes.

Reproduction is sexual and the sexes are separate. Embryos are brooded by the female in a series of dorsal brood pouches during early development. The species is poecilogonous, i.e., it exhibits two distinct, genetically determined developmental strategies. Some females exhibit planktotrophic brood development in which a relatively large number of small eggs develop into small planktotrophic larvae. In contrast, other females exhibit lecithotrophic brood development, in which fewer, larger offspring spend only a short time in the water column and subsist on yolk reserves rather than feeding in the plankton prior to settlement to the benthic environment. Egg diameters in planktotrophic forms range around 60-70 µm, while those from Lecithotrophic forms measure 100-200 µm. Brood sizes from planktotrophic females range from 15 to 70 individuals, whereas those from lecithotrophic females range from around 70 to more than 460 individuals.

Planktotrophic larvae bear long swimming setae typical of many spionid polychaete larvae. They are released from brood pouches at around 250-300 µm and live and feed in the plankton for up to 7 weeks. In contrast, non-feeding lecithotrophic larvae are considerably larger (550-650 µm) at the time of release, and lack swimming setae. They are metamorphically competent (capable of immediate settlement), but typically remain in the water column for a period of time ranging from a few hours to just over one week.

Age: 30 to 75 weeks

Synonym (s)
Streblospio lutincola Hartman, 1936
(Heterotypic synonym)

Common Name (s)
Economic Importance and Threats
Importance:  Ecosystem balance
(It is important as a food resource to a number of estuarine consumer species. It has also been used as a marine nutrient pollution indicator organism.


Habitat:  Benthic, Estuarine, Sandy, Muddy, Coastal
Trophic Level:  Consumer
Predator:  Grass shrimp (Palaemonetes pugio), blue crabs (Callinectes spp.), and juvenile fish like spot (Leiostomus xanthurus) and flounder.


• Maharashtra, Dabhol INDIA (Record: 12/1994, 12/1996)
• Goa, Miramar INDIA (Record: 10/2000)

Literature Source(s)
  • Ingole, BS; Rodrigues, N and Ansari, ZA (2002) Macrobenthic communities of the coastal waters of Dabhol, west coast of India Indian Journal of Marine Sciences NISCAIR, CSIR 31 93-99 Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Smithsonian Marine Station at Fort Pierce Available at -
  • Mascarenhas, a and Ingole, BS (2009) Miramar (Goa) beach management project: An oceanographic evaluation Coastal environments: Problems and perspectives A.C.I.K. Int. Pub. House; New Delhi; India 212-225 Available at - NIO, Goa

Page last updated on:2010-12-07

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