Slipper Lobster

Common Name(s)

Flathead lobster, Bay lobster ; French: Cigale raquette ; Spanish: Cigarra chata

High Risk

No data available OR Proven poor fishery status and/or high risk of decline to poor status without appropriate management / ineffective management and/or high environmental impact. If species is listed as vulnerable, endangered or critically endangered then stop sourcing.

Traditional Chinese

琵琶蝦 ("Pei Pa Ha")

Filipino

Cupapa

Thai

Gang-gra-daan

Malaysian

Udang lobok

Japanese

Uchiwa-ebi-modoki

Simplified Chinese

东方扁虾

Date of Assessments

July 2020

Peer Reviewer

Dr Yvonne Sadovy, Honorary Professor, The University of Hong Kong

Assessment Organisation

The University of Hong Kong

SEASONAL AVAILABILITY

Overview

The slipper or flathead lobster (Thenus orientalis) has a strongly depressed body and grows to a maximum body length of 25 cm (9.8 in), or a carapace length of 8 cm (3.1 in).
Thenus orientalis has an Indo-West Pacific distribution, ranging from the east coast of Africa (southern Red Sea, to Natal) to China including the Persian Gulf, southern Japan, the Philippines and along the northern coast of Australia from Western Australia to Queensland. They are also caught on a small scale off the shores of Malaysia and Singapore.
This species is found on sandy coarse substrates and mud with possibly shells and gravel at depths of 8 – 100 m, although it is more commonly found from 10 – 50 m (Holthuis 1991).
This is a slow growing species with a well-defined breeding period (Radhakrishnan et al.2005). The high fecundity, wide dispersal and long-lived nature of this species larvae render this species resilient to complete local extinction from an area (Mikami and Greenwood 1997).
Average size (total length) at maturity is 10.7cm.

Annual production of slipper lobsters generally has been around 5,000 tonnes, the majority of which is production of Thenus orientalis in Asia.
Thenus orientalis is caught as by-catch in some areas, and is targeted in others (Radhakrishnan et al. 2005).
This species is currently threatened by over-fishing, which has caused localized declines and collapses of some fisheries (Radhakrishnan et al.2005).
Although they are fished for wherever they are found, slipper lobsters have not been the subject of such intense fishery as spiny lobsters or true lobsters. The methods used for catching slipper lobsters varies depending on the species’ ecology. Those that prefer soft substrates, such as Thenus spp. are often caught by trawling.

Trawl

A fishing method that uses one or several nets with an otter board to keep the net open horizontally. The net will be towed from the stern of the boat and can be either demersal (on/near sea bed) or pelagic (mid-water). Bottom trawling is a type of trawling that sets the nets on the seaﬂoor. Heavy weights are attached to the nets to stir up the sand or mud so that fish and shrimp living there can be caught. Sometimes heavy rockhoppers are used, chains with roller wheels that allow the net to roll over rough, rocky seabeds without damaging the nets or being stopped by the rock.

Evidence of the catch certificate showing the following:
- latin species name,
- country sea area / RFMO area,
- vessel flag,
- name of vessel,
- Unique Vessel Identifier,
- capture method,
- landing port
Is the fishery in a fishery improvement project?

COUNTRY SPECIFIC RISK ASSESSMENTS

Thailand

Thenus orientalis from fisheries in Thailand can be considered to be a high risk.
There is limited information on the status of orientalis in Thailand, however Catch Per Unit Effort (CPUE) is likely decreasing.
Although orientalis is widespread globally, it’s high economic value and vulnerability to being captured in bottom trawls mean it is susceptible to overfishing at a local level.
There are no management measures in place in Thailand that restrict harvesting of this species.
Bottom trawling in tropical fisheries can be an indiscriminate method of fishing, with potential for high levels of bycatch.

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