Rapana venosa

Rapana venosa

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Overview

Brief Summary

Rapana venosa is a large predatory marine snail that is native to marine and estuarine waters of the western Pacific, from the Sea of Japan, Yellow Sea, East China Sea and Bohai Sea (Richerson 2006). It is now also established in many other parts of the world, where it is generally viewed as an invasive species with the potential to have a seriously negative impact.

In the Black Sea, Rapana venosa occurs down to 30 m in depth in areas with sandy bottoms, as well as in rocky and muddy habitats (Culha et al. 2009). Harding and Mann (1999) report that in the lower Chesapeake Bay (USA), Rapana venosa inhabits subtidal hard bottom habitats, where it can feed, mate, and move while completely burrowed. Rapana venosa is ecologically flexible, able to tolerate low salinity, low oxygen, and significantly polluted water (Gilberto et al. 2006; Culha et al. 2009).  It feeds at night and is often found in locations that are hard to sample, making early detection of newly established populations difficult (Harding et al. 2007). 

Working with animals from the Chesapeake Bay region (Virginia, USA), Harding et al. (2007) found significant differences in predation strategies and prey species consumed between the introduced veined Rapana venosa and the smaller, native Atlantic oyster drills (Urosalpinx cinerea). As Rapana venosa becomes more prevalent, these differences could result in considerable disruption of the trophic structure (feeding relationships among species) of Chesapeake Bay.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Description

Morphology

The shell of Rapana venosa is globose (rounded) with a very short-spired shell and a large body whorl.  The epidermal color varies from gray to reddish-brown, with dark brown dashes on the spiral ribs.  Most specimens have distinctive black veins throughout the shell.  A diagnostic feature for this species is the deep orange color found in the aperture and on the columella (Richerson 2006).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Size

May exceed 160 mm in length (Harding et al. 2007).

Can reach 180 mm (Richerson 2006).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Taxon Biology

Rapana venosa is a large predatory marine snail that has recently become established in a number of areas outside its native range, raising concerns about potentially serious ecological and economic impacts as it expands into new regions.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Ecology

Habitat

In the Black Sea, Rapana venosa occurs down to 30 m in depth in areas with sandy bottoms, as well as in rocky and muddy habitats (Culha et al. 2009).

Harding and Mann (1999) report that in the lower Chesapeake Bay (USA), Rapana venosa inhabits subtidal hard bottom habitats, where it can feed, mate, and move while completely burrowed.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Ecology

Rapana venosa is ecologically flexible, able to tolerate low salinity, low oxygen, and significantly polluted water (Gilberto et al. 2006; Culha et al. 2009).  It feeds at night and is often found in locations that are difficult to sample, making early detection of newly established populations difficult (Harding et al. 2007).

Harding et al. (2007) studied predation signatures of Rapana venosa, such as distinctive bore holes in prey shell remains (only R. venosa individuals too small to grasp and manipulate prey leave visible predation signatures). These signs could provide a powerful surveillance tool, allowing early detection of smaller, pre-reproductive animals than is possible by simply waiting for their appearance as fishing bycatch (R. venosa are likely to be caught by fishermen only once a population is well established and significant numbers of larger animals are present).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Distribution

Rapana venosa is native to marine and estuarine waters of the western Pacific, from the Sea of Japan, Yellow Sea, East China Sea and Bohai Sea (Richerson 2006). It is now also established in many other parts of the world, where it is generally viewed as an invasive species with the potential to have a seriously negative impact.

According to Culha et al. (2009) and references therein:  Rapana venosa became established in the Black Sea in the 1930s and 1940s and spread over the coasts of the Caucasus, the Crimea, and the Azov Sea over a period of 10 years. It expanded its distribution toward the Turkish and Bulgarian coasts of the Black Sea and the coasts of Romania during 1959-1972. It has also been reported from the southeastern coast of South America and from the Red Sea and many localities in the Adriatic Sea since the 1980s. It was presumably introduced into these areas accidentally by ships.

The first specimen in North America was collected by members of the Virginia Institute of Marine Science Trawl Survey Group in August 1998 in Hampton Roads, Virginia (Harding and Mann 1999). Harding and Mann (2005) documented three range extensions of Rapana venosa in Chesapeake Bay, Virginia. These extensions into Tangier Sound, the mid James River estuary, and to Cape Henry at the Bay mouth extended respectively, the northern, western, and southeastern boundaries of the known occupied range in Virginia waters. Salinity and tidal circulation mediate the distribution of adults and larvae of this animal. During dry years (e.g., 2001 and 2002) adult R. venosa may move up-estuary in western tributaries like the James River, given increased salinity and available habitat and food resources. Declines in salinities (or return to normal salinities) will either kill the whelks in the upriver habitats or force a return to downstream habitats (Harding and Mann 2005). The species is now widely distributed in Chesapeake Bay, which harbors what is still the only known breeding population in North America (Harding et al. 2008). 

Gilberto et al. (2006) studied a recently established population of Rapana venosa in the Rio de la Plata estuary along the southeastern coast of South America (Uruguay/Argentina).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Cyclicity

Culha et al. 2009: Moves between warmer deep waters in winter and coastal regions in summer.

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Life Expectancy

12-18 years (Harding et al. 2007)

10-15 years (Harding et al. 2008)

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Reproduction

The reproductive biology of Korean Rapana venosa was investigated by Chung et al. (2002). They found that the total number of egg capsules per individual each year (based on 25 whelks in aquaria) ranged between 184 and 410. The mean number of eggs per egg caspsule was 976. Annual fecundity ranged from about 179,000 to 400,000 eggs per individual, with two to four broods during the spawning season. Eggs in egg capsules, which may be attached to various hard substrates (Culha et al. 2009), took 15 to 17 days at about 20 C to develop and hatch out veliger larvae. No significant deviation was detected from a 1:1 sex ratio.

Harding et al. (2008) investigated the reproductive biology of Rapana venosa from the Chesapeake Bay region (USA) and found even higher productivity, with the number of egg capsules per whelk per year ranging from 133-2759 divided among 3 to 29 broods.  They found that egg capsule production is influenced by seasonal and absolute water temperatures as well as by seasonal daylength cycles. Egg capsule deposition by Chesapeake Bay R. venosa begins at water temperatures of approximately 18 degrees C and continues for 11-15 weeks. Forty to 70% of female whelks deposited egg capsules in most weeks during this season, producing 150-200 egg capsules per female per week. Water temperatures above 28 degrees C caused reduced egg capsule production relative to temperatures of 20-25 degrees C. Egg capsule production was positively related to seasonal changes in daylength, and two peaks of egg capsule deposition were observed in the 2001 and 2002 deposition seasons. The combination of declining daylength and higher water temperatures in late summer was associated with the cessation of egg capsule deposition. The authors predict a latitudinal range of 30-41 degrees (north and south) as the realized reproductive range for Rapana venosa populations based on the environmental requirements for native whelks and reproductively active invasive Rapana venosa populations (Harding et al. 2008).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Associations

Harding et al. (2009) reported significant mortality of Rapana venosa during a bloom of the dinoflagellate Alexandrium monilatum in the lower York River, Virginia (USA) in September 2007. The whelks stopped feeding as dissolved oxygen and chlorophyll concentrations increased with the development of the bloom. Harding et al. noted that whelk mortality was preceded by external signs of stress including reduced ventilation, inability to attach to hard substrates, periodic pumping of the opercular plate, and increased mucus production over a period of 24-48 hours prior to death. High concentrations of goniodimum A (a toxin produced by A. monilatum) were observed in bivalves attached to the shells of R. venosa. Mortality of R. venosa was 100%. Mortality of oysters (Crassostrea virginica) and northern quahog clams (Mercenaria mercenaria) in the same flow-through system was 0%. The symptoms displayed by the R. venosas in the 24-48 hours prior to death were indicative of paralysis and followed a timecourse similar to that documented for some other molluscs exposed to toxic A. monilatum.

Savini et al. (2002) suggested that the introduction of Rapana venosa to Chesapeake Bay (U.S.A.) offers cause for both ecological and economic concern. Adult Rapana venosa are large predatory gastropods that consume bivalves including commercially valuable species such as hard clams (Mercenaria mercenaria). Laboratory feeding experiments were used to estimate daily consumption rates of two sizes of whelks feeding on two size classes of hard clams. Large R. venosa (shell length, SL > 101 mm) are capable of consuming up to 2.7 g wet weight of clam tissue daily, equivalent to 0.8% of their body weight. Small whelks (60-100 mm SL) ingest an average of 3.6% of their body weight per day.

Very large striped hermit crabs (Clibinarius vittatus) have begun to use shells of the exotic Rapana venosa as shelters (Harding and Mann 1999).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Relevance

Risk Statement

Working with animals from the Chesapeake Bay region (Virginia, USA), Harding et al. (2007) found significant differences in predation strategies and prey species consumed between the introduced veined Rapana venosa and the smaller, native Atlantic oyster drills (Urosalpinx cinerea). As Rapana venosa becomes more prevalent, these differences could result in considerable disruption of the trophic structure (feeding relationships among species) of Chesapeake Bay.

To date, there has been no successful eradication of any nonindigenous marine invertebrate in the United States. The potential for Rapana venosa to cause significant harm to the Chesapeake region's native shellfish and seafood industry is a serious concern (Richerson 2006).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

Uses

Rapana venosa is of significant economic value on the coasts of the Black Sea and is regularly collected during certain periods (Culha et al. 2009). However, this species has a negative impact on commercial shellfish species in both its native and introduced ranges (Harding et al. 2008).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo

References

Chung, E. Y., Kim S. Y., Park K. H., & Park G. M. (2002).  Sexual maturation, spawning, and deposition of the egg capsules of the female purple shell, Rapana venosa (Gastropoda : Muricidae). Malacologia. 44, 241-257.
Culha, M., Bat L., Dogan A., & Dagli E. (2009).  Ecology and Distribution of the Veined Rapa Whelk Rapana venosa (Valenciennes, 1846) in Sinop Peninsula (Southern Central Black Sea), Turkey. Journal of Animal and Veterinary Advances. 8, 51-58.
Gilberto, D. A., Bremec C. S., Schejter L., Schiariti A., Mianzan H., & Acha E. M. (2006).  The invasive rapa whelk Rapana venosa (Valenciennes 1846): Status and potential ecological impacts in the Rio de la Plata estuary, Argentina-Uruguay. Journal of Shellfish Research. 25, 919-924.
Harding, J. M., & Mann R. (1999).  Observations on the biology of the Veined Rapa whelk, Rapana venosa (Valenciennes, 1846) in the Chesapeake Bay. Journal of Shellfish Research. 18, 9-17.
Harding, J. M., & Mann R. (2005).  Veined rapa whelk (Rapana venosa) range extensions in the Virginia waters of Chesapeake Bay, USA. Journal of Shellfish Research. 24, 381-385.
Harding, J. M., Kingsley-Smith P., Savini D., & Mann R. (2007).   Comparison of predation signatures left by Atlantic oyster drills (Urosalpinx cinerea Say, Muricidae) and veined rapa whelks (Rapana venosa Valenciennes, Muricidae) in bivalve prey. Journal of Experimental Marine Biology and Ecology. 352, 1-11.
Harding, J. M., Mann R., & Kilduff C. W. (2008).  Influence of environmental factors and female size on reproductive output in an invasive temperate marine gastropod Rapana venosa (Muricidae). Marine Biology. 155, 571-581.
Harding, J. M., Mann R., Moeller P., & Hsia M. S. (2009).  Mortality of the veined rapa whelk, Rapana venosa, in relation to a bloom of Alexandrium monilatum in the York River, United States. Journal of Shellfish Research. 28, 363-367.
Savini, D., Harding J. M., & Mann R. (2002).   Rapa whelk Rapana venosa (Valenciennes, 1846) predation rates on hard clams Mercenaria mercenaria (Linnaeus, 1758). Journal of Shellfish Research. 21, 777-779.