Global invasive species database

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Common name
Asian calanoid copepod (English)
Synonym
Similar species
Summary
Pseudodiaptomus inopinus is endemic to the Indo-Pacific region including southeast Asia. It was introduced to Pacific Northwest estuaries via ballast water between 1980 and 1990 and has rapidly expanded in range since then. It has persisted in many estuaries between southern Washington and southern Oregon. It appears to be a stable and dominant component of zooplankton there. The dominance of P. inopinus in several estuaries will likely alter the food web and ecosystem dynamics, but to what extent is unknown.
Species Description
Pseudodiaptomus inopinus is typically 1-2mm long, with a teardrop shaped body and large antennae.It has an armoured exoskeleton which is almost totally transparent (Wikipidea 2006).
Uses
Pseudodiaptomus inopinus is an important, perhaps even dominant component of the diet of bentho-pelagic invertebrate predators in its introduced range (e.g. mysids and Crangon shrimp), and shares a vertical distribution and migration pattern with these predators (dwells in the bottom during the day, and up in the water column at night) (Bollens et al., 2002).
Habitat Description
In its native Asia P. inopinus occurs in a variety of fresh\r\nwater and estuarine habitats (Shen and Song 1979). It is most abundant in autumn (Shen and Song 1979), and appears to be part of an assemblage that occurs mainly in the fluvial-oligohaline reaches of the estuary at salinities of 0-5 psu (Cordell & Morrison 1996).

\r\nIn its introduced habitat P. inopinus has only invaded coastal estuaries with relatively high temperatures, low elevation gradients and large salinity transition zones. It is confined predominantly to the lower salinity (<10 psu) reaches of estuaries, with peak abundances occurring in the 2-5 psu range (Bollens et al. 2002).

Pathway

Principal source:

Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)

Review: Jeffery R. Cordell. Principal Research Scientist School of Aquatic and Fishery Sciences University of Washington, Seattle USA

Publication date: 2007-05-11

Recommended citation: Global Invasive Species Database (2021) Species profile: Pseudodiaptomus inopinus. Downloaded from http://www.iucngisd.org/gisd/speciesname/Pseudodiaptomus+inopinus on 26-10-2021.

General Impacts
P. inopinus may dominate plankton assemblages in the low salinity zones of estuaries it has invaded. Where does P. inopinus fit into estuarine ecosystems? Where does it fit into the food chain? Can it significantly impact ecosystems and food chains? Such questions are being addressed by researchers Cordell Rasmussen and Bollens (2007), whose work suggests that P. inopinus may dominate plankton assemblages in low salinity zones of estuaries where it has been introduced. The authors found that other abundant planktonic copepods were separated from P. inopinus at the estuarine study site either temporally (Eurytemora affinis) or spatially (Acartia spp., E. americana) (Cordell Rasmussen and Bollens 1998, in Cordell Rasmussen and Bollens 2007). This separation implies that P. inopinus experienced little competition when it was introduced or, alternatively, it may have altered the distribution of other copepods in the estuary following introduction. \r\n

Due to competition for limiting resources (eg: phytoplankton food), predation, or some other coincidental factors, the invasion of this Asian copepod may have caused dramatic food web and ecosystem changes in estuaries. P. inopinus may have the potential to alter the energy and nutrient flow of an ecosystem and may replace or reduce pre-existing native estuarine zooplankton populations. Such changes in energy flow could have higher level effects on juvenile salmon and other commercially important species (Bollens et al 2002). Such fears are precipitated because of other examples, such as, the invasion of the northwestern Atlantic ctenophore Mnemiopsis leidyi in the Black and Azov Seas, which possibly triggered significant ecosystem changes to cause declines in numbers of commercially important species (Shiganova and Bulganova 2000, Kideys 2002, Bilio and Niermann 2004, in Cordell Rasmussen and Bollens 2007). \r\n

Research by Cordell Rasmussen and Bollens (1998) found that although P. inopinus was rare in the diets of estuarine fishes, it comprised\r\nan important and sometimes dominant prey for mysid shrimp Neomysis mercedis which were in turn preyed upon by fish. P. inopinus was also an important component of the diet of juvenile caridean shrimp (Crangon franciscorum). In conclusion P. inopinus indirectly supplied an important food source to fish via the mysid shrimp pathway. For a discussion on the relation between abundance of this copepod and flooding events / temperature please see Cordell Rasmussen and Bollens 2007.

Management Info
Preventative measures: P. inopinus spread can be prevented by draining water from boats or other equipment when leaving a body of water, and by emptying bait buckets on land or into the trash (WSGP, 2000). Furthermore, legislation applicable to coastal shipping may also be useful for prevention (Falkner, 2003).
Countries (or multi-country features) with distribution records for Pseudodiaptomus inopinus
ALIEN RANGE
NATIVE RANGE
  • asia
Informations on Pseudodiaptomus inopinus has been recorded for the following locations. Click on the name for additional informations.
Lorem Ipsum
Location Status Invasiveness Occurrence Source
Details of Pseudodiaptomus inopinus in information
Status
Invasiveness
Arrival date
Occurrence
Source
Introduction
Species notes for this location
Location note
Management notes for this location
Impact
Mechanism:
Outcome:
Ecosystem services:
Impact information
P. inopinus may dominate plankton assemblages in the low salinity zones of estuaries it has invaded. Where does P. inopinus fit into estuarine ecosystems? Where does it fit into the food chain? Can it significantly impact ecosystems and food chains? Such questions are being addressed by researchers Cordell Rasmussen and Bollens (2007), whose work suggests that P. inopinus may dominate plankton assemblages in low salinity zones of estuaries where it has been introduced. The authors found that other abundant planktonic copepods were separated from P. inopinus at the estuarine study site either temporally (Eurytemora affinis) or spatially (Acartia spp., E. americana) (Cordell Rasmussen and Bollens 1998, in Cordell Rasmussen and Bollens 2007). This separation implies that P. inopinus experienced little competition when it was introduced or, alternatively, it may have altered the distribution of other copepods in the estuary following introduction. \r\n

Due to competition for limiting resources (eg: phytoplankton food), predation, or some other coincidental factors, the invasion of this Asian copepod may have caused dramatic food web and ecosystem changes in estuaries. P. inopinus may have the potential to alter the energy and nutrient flow of an ecosystem and may replace or reduce pre-existing native estuarine zooplankton populations. Such changes in energy flow could have higher level effects on juvenile salmon and other commercially important species (Bollens et al 2002). Such fears are precipitated because of other examples, such as, the invasion of the northwestern Atlantic ctenophore Mnemiopsis leidyi in the Black and Azov Seas, which possibly triggered significant ecosystem changes to cause declines in numbers of commercially important species (Shiganova and Bulganova 2000, Kideys 2002, Bilio and Niermann 2004, in Cordell Rasmussen and Bollens 2007). \r\n

Research by Cordell Rasmussen and Bollens (1998) found that although P. inopinus was rare in the diets of estuarine fishes, it comprised\r\nan important and sometimes dominant prey for mysid shrimp Neomysis mercedis which were in turn preyed upon by fish. P. inopinus was also an important component of the diet of juvenile caridean shrimp (Crangon franciscorum). In conclusion P. inopinus indirectly supplied an important food source to fish via the mysid shrimp pathway. For a discussion on the relation between abundance of this copepod and flooding events / temperature please see Cordell Rasmussen and Bollens 2007.

Red List assessed species 0:
Management information
Preventative measures: P. inopinus spread can be prevented by draining water from boats or other equipment when leaving a body of water, and by emptying bait buckets on land or into the trash (WSGP, 2000). Furthermore, legislation applicable to coastal shipping may also be useful for prevention (Falkner, 2003).
Locations
Management Category
Monitoring
Bibliography
10 references found for Pseudodiaptomus inopinus

Management information
Centre for Environment, Fisheries & Aquaculture Science (CEFAS)., 2008. Decision support tools-Identifying potentially invasive non-native marine and freshwater species: fish, invertebrates, amphibians.
Summary: The electronic tool kits made available on the Cefas page for free download are Crown Copyright (2007-2008). As such, these are freeware and may be freely distributed provided this notice is retained. No warranty, expressed or implied, is made and users should satisfy themselves as to the applicability of the results in any given circumstance. Toolkits available include 1) FISK- Freshwater Fish Invasiveness Scoring Kit (English and Spanish language version); 2) MFISK- Marine Fish Invasiveness Scoring Kit; 3) MI-ISK- Marine invertebrate Invasiveness Scoring Kit; 4) FI-ISK- Freshwater Invertebrate Invasiveness Scoring Kit and AmphISK- Amphibian Invasiveness Scoring Kit. These tool kits were developed by Cefas, with new VisualBasic and computational programming by Lorenzo Vilizzi, David Cooper, Andy South and Gordon H. Copp, based on VisualBasic code in the original Weed Risk Assessment (WRA) tool kit of P.C. Pheloung, P.A. Williams & S.R. Halloy (1999).
The decision support tools are available from: http://cefas.defra.gov.uk/our-science/ecosystems-and-biodiversity/non-native-species/decision-support-tools.aspx [Accessed 13 October 2011]
The guidance document is available from http://www.cefas.co.uk/media/118009/fisk_guide_v2.pdf [Accessed 13 January 2009].
Falkner, M.B. 2003, Report on the California Ballast water management program, California State Lands Commission Marine Facilities Division, February, unpublished.
Summary: This is report produced for the California State Legislature. AB 703 established the California Ballast Water Management for Control of Nonindigenous Species Act during the 1999 legislative session to address the introduction of nonindigenous aquatic species. This report summarizes the ballast water management activities in California during the first 2.5 years of the Program and makes recommendations for amendments to the Act based on the effectiveness of the State�s program.
Washington Sea Grant Program (WSGP) 2001, A guide to least-wanted aquatic organisms of the Pacific Northwest-aquatic invasive species, University of Washington.
Summary: This paper lists a number of wanted aquatic organisms of Pacific Northwest, and provides information general description, impacts and management for each one of them.
Available from: http://www.wsg.washington.edu/outreach/mas/nis/leastwanted.pdf [Accessed 27 Novemeber 2006].
General information
Bollens, S.M., Cordell, J.R., Avent, S. and Hooff, R. 2002 Zooplankton invasions: a brief review, plus two case studies from the northeast Pacific Ocean, in Hydrobiologia 480: 87-110
Summary: This paper reviewed the current state of research on nonindigenous zooplankton, and included preliminary results from two ongoing studies of invasive zooplankton in the northeast Pacific Ocean- the Asian copepods Pseudodiaptomus inopinus in Washington and Oregon coastal estuaries, and Tortanus dextrilobatus in San Francisco Bay Estuary.
Cordell, J.R. and Morrison, S.M. 1996. The invasive Asian Copepod Pseudodiaptomus inopinus in Oregon, Washington, and British Columbia Estuaries, in Estuaries19: 629-638
Summary: This study is to survey river estuaries in Oregon and Washington and in southern British Columbia, Canada, for the presence of P. inopinus. It aims to gather preliminary data on how widespread exotic copepods are in this region s estuaries and the distribution in rivers in relation to the salinity and gradient.
Cordell, J.R. and Rassmussen, M. 2001. An exotic copepod in Pacific Northwest Estuaries. In Abstracts: Second International Conference on Marine Bioinvasions, March 9-11, 2001. New Orleans, LA.
Summary: Study into the effects of an exotic copepod invasion in Pacific Northwest Estuaries.
ITIS (Integrated Taxonomic Information System), 2005. Online Database Pseudodiaptomus inopinus.
Summary: An online database that provides taxonomic information, common names, synonyms and geographical jurisdiction of a species. In addition links are provided to retrieve biological records and collection information from the Global Biodiversity Information Facility (GBIF) Data Portal and bioscience articles from BioOne journals.
Available from: http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=331702 [Accessed 23 August 2006]
The Ocean Biogeographic Information System (OBIS) Pseudodiaptomus inopinus
Summary: The Ocean Biogeographic Information System (OBIS) is the information component of the Census of Marine Life (CoML), a growing network of more than 1000 researchers in 73 nations engaged in a 10-year initiative to assess and explain the diversity, distribution, and abundance of life in the oceans - past, present, and future. OBIS is a web-based provider of global geo-referenced information on marine species. OBIS contains expert species level and habitat level databases and provide a variety of spatial query tools for visualizing relationships among species and their environment.
This page available from: http://www.iobis.org/OBISWEB/ObisControllerServlet?searchName=Pseudodiaptomus+inopinus+&category=all&names=data&x=25&y=12 [Accessed 23 August 2006]
Ocean Biogeographic Information System (OBIS) available from: www.iobis.org
United States Geological Survey, 2006 Pseudodiaptomus inopinus , USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
Summary: This wedsite provides information about the common name of Pseudodiaptomus inopinus.
Availbale from: http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=176 [Accessed 27 November 2006].
Contact
The following 1 contacts offer information an advice on Pseudodiaptomus inopinus
Cordell,
Jeffery R.
Webpage
Dr. Cordell s research interests encompass four major foci: Biology and Ecology of Copepoda- investigating which types of habitats are important in producing fish prey copepods, and how human impacts affect these habitats; The Role of Exotic Invertebrates in Pacific Northwest Estuaries- understanding the ecological affects of introduced small marine invertebrates; Biological Functions of Restored Estuarine Wetlands- measuring recolonisation of restored estuarine wetlands by invertebrates and juvenile salmon and using the results to evaluate the effectiveness of restoration techniques; and, Taxonomy of Small Crustaceans.
Organization:
Principal Research Scientist
Address:
School of Aquatic and Fishery Sciences 1122 Boat Street University of Washington, Box 355020 Seattle, WA 98195-5020
Phone:
206-543-7532
Fax:
Pseudodiaptomus inopinus
Asian calanoid copepod
Date assessed
Year published
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Recommended citation
(2021). Pseudodiaptomus inopinus. IUCN Environmental Impact Classification for Alien Taxa (EICAT).