Sampling event

First record of male freshwater eels (Anguilla dieffenbachii) caught at sea

Latest version published by The National Institute of Water and Atmospheric Research (NIWA) on 17 January 2024 The National Institute of Water and Atmospheric Research (NIWA)

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Description

Two silver (migratory) male freshwater eels, Anguilla dieffenbachii, were caught in a commercial trawl net in the South Taranaki Bight in April 2014. The capture date and the relatively small eye size indicated that both eels had probably only recently entered the sea. This is the first record of male A. dieffenbachii caught at sea, en route to the presumed spawning area in the South Fiji Basin

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 1 records.

2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

Event (core)
1
ExtendedMeasurementOrFact 
3
Occurrence 
2

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Jellyman D J, Stewart A (2024). First record of male freshwater eels (Anguilla dieffenbachii) caught at sea. Version 1.2. The National Institute of Water and Atmospheric Research (NIWA). Samplingevent dataset. https://nzobisipt.niwa.co.nz/resource?r=nz_male_anguilla_at_sea&v=1.2

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is The National Institute of Water and Atmospheric Research (NIWA). This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: c16b2618-357a-478c-963c-63ee380f1e80.  The National Institute of Water and Atmospheric Research (NIWA) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by GBIF New Zealand.

Keywords

Samplingevent

Contacts

Don J. Jellyman
  • Metadata Provider
  • Originator
  • Point Of Contact
Researcher
National Institute of Water & Atmospheric Research
Christchurch
NZ
Andrew Stewart
  • Originator
Researcher
Museum of New Zealand, Te Papa Tongarewa
Wellington
NZ

Geographic Coverage

South Taranaki Bight, New Zealand

Bounding Coordinates South West [-40.4, 174.45], North East [-40.3, 174.55]

Taxonomic Coverage

New Zealand Longfin Eel

Species Anguilla dieffenbachii (New Zealand longfin eel, ōrea)

Temporal Coverage

Start Date / End Date 2014-04-21 / 2014-04-22

Sampling Methods

On 22 April 2014, two A. dieffenbachii were caught in the D'Urville Sea Valley, South Taranaki Bight, by a commercial trawler; the centroid of the trawl shot, 40 22’S, 174 03E, was 36 km NNE of Stephens Island (Marlborough Sounds), and 98 km West of Foxton Beach. The trawl (116 m opening, 60 m height, 108 mm codend mesh) was deployed at 2140 h on 21 April and retrieved at 0600 h the following day. The average bottom depth was 122 m, but as the trawl fished mid-water, the actual depth of capture is uncertain. The eels were noticed by Ministry for Primary Industries onboard observers who froze them prior to forwarding to the Museum of New Zealand, Te Papa Tongarewa, for confirmation of identification.

Study Extent South Taranaki Bight

Method step description:

  1. When thawed, one eel measured 608 mm TL and 474 g, and the second 648 mm (but was not weighed). Both eels were identified as A. dieffenbachii from external features (body shape, colour, insertion and length of the dorsal fin and pattern of vomerine teeth), while examination of the gonads confirmed they were males. As they were catalogued as museum specimens, it was not permitted to make incisions and remove both testes, so no gonadosomatic index could be calculated. The eye indices (vertical x horizontal diameter; Todd Citation1981b) were 9.36 and 9.88 mm2 respectively; the average index for silver longfin male eels of similar lengths at the start of their seaward migration would be 9.2 and 10.26 mm2 respectively (calculated from the eye index/total length relationship given by Todd (Citation1981b)).

Bibliographic Citations

  1. Don J. Jellyman & Andrew I. Stewart (2019) First record of male freshwater eels (Anguilla dieffenbachii) caught at sea, New Zealand Journal of Marine and Freshwater Research, 53:2, 288-291 DOI: 10.1080/00288330.2018.1550792

Additional Metadata

marine, harvested by iOBIS

Alternative Identifiers c16b2618-357a-478c-963c-63ee380f1e80
https://nzobisipt.niwa.co.nz/resource?r=nz_male_anguilla_at_sea