Biology of the selected endangered species of sea cucumber

Biology of the selected endangered
species of sea cucumber
PRESENTED BY:
satyaveer
Jr.M.F.SC

 Holothurian commonly c/a sea
slugs or Sea cucumber.
 Sea cucumber is a group of
economically important
echinoderms.
 Sea cucumbers are found on the
sea floor worldwide.
 The number of
holothurian species worldwide is
about 1717 with the greatest
number being in the Asia Pacific
region.
INTRODUCTION

 sea cucumbers have a soft and cylindrical body, more or less
lengthened, rounded off and occasionally flat without solid
appendages.
 Their body shape is similar to a cucumber, but they have small
tentacle-like tube feet that are used for locomotion and feeding.
 Length -10 to 30 cm (3.9 to 11.8 in).
smallest 3 mm (0.12 in) long, and
largest 3 meters (9.8ft)
 The body wall consists of an epidermis and a dermis and
contains smaller calcareous ossicles.
CHARACTERISTICS OF SEA
CUCUMBER

Longest sea cucumber
3 meter (10 ft.)
Synapta maculata (Snake
Sea)
Thyonina bijui
Smallest sea cucumber
2 cm

 Most sea cucumber possess five rows of tube feet (called
“PODIA“) but Apodida lacks these and moves by crawling.
The podia on the dorsal surface generally have no locomotive
role,and are transformed into papillae.
 The anus is Postero-dorsal.

 The gut of sea cucumber is long and coiled.
 A long gut is advantageous in sea cucumber because they
need to remove organic matter from the large amount of
sediment they ingest.
 Respiratory exchange through body surface.
 They have complete digestive system.
 Sea cucumbers have no true brain.

 Sea cucumbers can be found at
deeper in ocean floor. But some
some species live on hard substrates
like rock, coral reef etc.
 Bentho pelagic sea
cucumber( Enypniastes) , have
webbed swimming structures
enabling them to swim up off the
surface of the seafloor and journey
as much as 1,000 m (3,300 ft) up the
water column.

 Holothuroidea are generally scavengers.
 The diet of most cucumbers consists of plankton and decaying
organic matter found in the sea.
Diet

 Most sea cucumbers reproduce by
releasing sperm and ova into the
ocean water
 Sexes are separate.
 Spawning behavior tends to be
seasonal.
 Sea cucumber breed twice in a year.
 Frist spawning season is March to
May & 2nd Oct to Dec in Gulf of
Mannar.
Reproduction

 Sea cucumbers have tough skins that probably lessen the risk of
predation.
 However, they do face the problem of being eaten by large marine
fish
PREDATORS

 Many sea cucumber have evolved
novel defensive mechanism that
compensate for the lack of a spines.
 Some secrete toxic substances
when disturbed, some sp.
 Discharge sticky filaments through
the anus to discourage potential
predators.
DEFENSIVE MECHANISM
Sea cucumber ejects sticky filaments
from the anus in self-defense.

 The sea cucumber is effective in treating cancer, arthritis, asthma
heal internal, hypertension and other diseases.
 Sea cucumber species were collected for processing as beche-de-
mer (trepang).
 Sea cucumber extracts are prepared and made into oil, cream, or
cosmetics.
 sea cucumber contains all the fatty acids necessary to play a
potentially active role in tissue repair.
Economical Uses and Biological
Significance

Endangered species of
sea cucumber
Thelenota ananas
(Prickly Redfish)
Holothuria nobilis
(Black Teat fish)
Actinopyga agassizi
(5 teethed sea cucumber)
Apostichopus japonicus
(Japanese spiky)

Conti…..
Holothuria scabra
(Golden Sandfish)
Apostichopus parvimensis
(Warty Sea Cucumber
Holothuria cinerascens
(Ashy Sea Cucumber)
Holothuria impatiens
(Bottleneck Sea Cucumber )

 Kingdom - Animalia
 Phylum - Echinodermata
 Class – Holothuroidea
 Order - Aspidochirotida
 Family - Holothuriidae
 Scientific Name: Holothuria scabra
 Common Name/s: Golden Sandfish,
Sandfish
 Red List Category &Criteria:Endanger
Holothuria scabra (Golden Sandfish)
Classification

 This species is wide spread throughout the Indo-Pacific between
latitudes 30°N and 30°S.
 Size:
Maximum length 40 cm, wet 2.0 kg
Avgr length 24 cm,wet 300 g
 HABITAT AND BIOLOGY:
 Found in shallow waters. Commonly found on inner flat reefs of
fringing and lagoonal reefs, and coastal sand flats and sea grass
beds with muddy sandy substrates, near mangroves.
 Attains size-at-maturity at about 25 cm in India sexually mature at
18 months.
DISTRIBUTION

 This species is one of the most valuable species of holothurian and
it is intensively exploited in many tropical countries for trade in
the Asian markets.
 This species has been heavily exploited in many parts of its range,
and is also in a bycatch of prawn nets in Madagascar.
EXPLOITATION

 Order – Aspidochirotida
 Scientific Name - Holothuria nobililis
 Common Name/s: Black Teatfish
 Red List Category & Criteria:Endangered
2.Holothuria nobilis
Classification

 This is present in the Africa and Indian Ocean region , and Madagascar, East
Africa, India, Sri Lanka, the Maldives and the Red Sea.
Habitat –
 This species is largely restricted to shallow coral reef habitat & shallow
sea grass beds.
 This species is common in shallow waters of reef bottom , at depths from
0 to 40 m.
 They prefer sandy hard substrate.
DISTRIBUTION

Size:
 Maximum length about 60 cm; average length about 35 cm.
Reproduction-:
The size at first sexual maturity is 9 cm in length.
This species is reported to mature at four years .
 It reproduces annually during the cold season.
 The gonads are long branched tubules; at maturity, they are white
in males and orange in females

 Fisheries: H. nobilis is one of the most valuable commercial
species and, therefore, is overexploited.
EXPLOITATION

 Family - Stichopodidae
 Scientific Name-Thelenota ananas
 Common Name/s:-Prickly Redfish
Red List Category & Criteria: Endangered
3.Thelenota ananas
Classification

 This species has a world wide distribution range throughout the Indo-Pacific, In
Madagascar, South Africa to India, southeast to Australia, north to Japan and
China.
Habitat-
They are distributed mainly in shallow coral reef areas, on reef flats, reef
slopes and near passes on sandy or hard bottoms with large rubble and coral
patches.
 It is common in shallow waters of reef bottom where there is no terrigenous
action, at depths from 0 to 20 m.
Reproduction-
Average length 45 cm & wt. - 1000 gm.
 It attains size-at-maturity at 1200 g and.
 Reproduces annually during the warm season.
DISTRUBUTION

 Scientific Name- Parastichopus californicus
 Red List Category & Criteria: Least Concern.
4.Parastichopus californicus
Classification

Size:
Maximum length about 50 cm.
Habitat and Biology:
 It occurs on a wide variety of substrates and current regimes, in water
depths from the intertidal to 250 m.
 This species is most abundant in areas of moderate current on
cobbles, boulders or bedrock,but avoids muddy bottoms and areas with
freshwater runoff.
Reproduction-
 It reproduces annually during the summer dry season (May–August)
and reproduction seems to be correlated with bright sunshine days and
high phytoplankton productivity.

Fisheries:
 Parastichopus californicus is exploited in industrial fisheries
by hand collection by trawling.
 The fishery of this species in Washington (USA) started in the
1970s, later spreading to California, Alaska and Oregon.
EXPLOITATION

 Class - Holothuroidea
 Scientific Name: Actinopyga agassizi
 Common Name/s: Five-toothed Sea Cucumber
 Red List Category & Criteria:Least Concern
5. Actinopyga agassizi
Classification

Size:
Maximum length about 35 cm.
 Sea cucumber species Nocturnal during the day, and inhabits
rocky areas, sea grass beds and coral reefs (including coral reef
lagoons) from shallow depths down to 54 m
 Feeds on detritus in the seafloor
 This species reproduces annually in July and August.
Habitat and Biolgy

Fisheries:
 This species is harvested, without any regulation, with other sea
cucumber species.
 There is commercial exploitation for bêche-de-mer in Panama
and Venezuela.
Threats
 Actinopyga agassizi is fished, however very little information is
known about the areas and quantities in which it is fished.
 Another potential threat is destruction of habitat in areas of high
coastal development
EXPLOITATION

 Class - Holothuroidea
 Scientific Name: Apostichopus japonicas
 Common Name/s: Japanese Spiky Sea Cucumber
 Red List Category & Criteria:Endangered
6. Apostichopus japonicus
Classification

 Apostichopus japonicus is found in shallow coastal bottom communities
from the intertidal zone to depths of 40 m.
 It forms aggregations, usually in the upper sub-littoral zone in the
subtropics.
 Juveniles are often associated with algal/sea grass and oyster beds.
Feeding habit
 Ingests organic matter, bacteria, protozoa, diatoms as well as plant and
animal detritus and re-utilizes residual food and faeces.
Reproduction
 Matures considerably earlier than other temperate species, at about two
years .
 Larval duration for this species is 12-13 days .
 This species typically grows to 20 cm in four years.
Habitat and Biology

 Sea cucumbers play a significant role in the ecological system.
 They help turn over sand in reef lagoons and sea grass beds.
 By feeding on dead organic matter mixed with sand and mud, the
nutrients they excrete can be again taken up by algae and corals –
a pathway of nutrient recycling on reefs.
 Sea cucumbers have also been found to buffer reefs from ocean
acidification.
 Feeding on reef sand by tropical sea cucumbers increases the
alkalinity in surrounding seawater.
 This may help to protect corals and other reef organisms from
ocean acidification.
Ecological Role

 sea cucumbers are at risk of extinction from their popularity on
dining tables, appreciated for their soft texture, dietary and
medicinal properties.
 Sea cucumber are facing extinction due to over exploitation.
 Due to illegal fishing .
 Eutrophication of the water in areas of coastal development is
another threat to this species.
 An additional threat is the harvesting of mature adults for brood
stock in aquaculture
THREATS

 Review and analysis of the available information on the global
status of commercially-exploited sea cucumber
 Stocks and identification of 'hot spots‘ to develop and implement
appropriate management approaches;
 Preparation of an identification guide for commercial sea
cucumbers, including the development of genetic markers
CONSERVATION

Biology of the selected endangered species of sea cucumber

Biology of the selected endangered species of sea cucumber

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