Tenellia adspersa

Researched By	Nicola White	Data Supplied By	MarLIN
Refereed by	Dr Richard S.K. Barnes
Taxonomy
Scientific name	Tenellia adspersa	Common name	Lagoon sea slug
MCS Code	W1443	Recent Synonyms	Tenellia pallida, Embletonia pallida
Phylum	Mollusca	Subphylum
Superclass		Class	Gastropoda
Subclass	Opisthobranchia	Order	Nudibranchia
Suborder		Family	Tergipedidae
Genus	Tenellia	Species	adspersa
Subspecies
Additional Information	No text entered
Taxonomy References	Howson & Picton, 1997, Picton & Morrow, 1994
General Biology
Growth form	Lanceolate	Feeding method	Predator
Mobility/Movement	Crawler	Environmental position	Epifaunal
Typical food types	Hydroids, especially %Cordylophora caspia%, Laomeda spp. and %Protohydra leuckarti%	Habit	Free living
Bioturbator	Not relevant	Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Very small(<1cm)
Height	Insufficient information	Growth Rate	Insufficient information
Adult dispersal potential	Not researched	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Tenellia adspersa can rapidly devour hydroid colonies, exhausting its own food supply. It has been suggested that the developmental plasticity and rapid growth of this species enables it to disperse to new locations to find new food.
Biology References	Antsulevich & Starobogatov, 1991
Distribution and Habitat
Distribution in Britain & Ireland	The few British records are from the Bristol Channel and the Fleet in Dorset.
Global distribution	Recorded from the eastern and western North Atlantic, Baltic, Mediterranean Sea, Black Sea, Azov Sea, Caspian Sea, Japan, Pacific coast of USA, Brazil
Biogeographic range	Not researched	Depth range	1 to 34 m
Migratory	Non-migratory / Resident
Distribution Additional Information	Recorded at depths from 1 to 34 m. The species has been observed to survive and breed in salinities from 50 psu to 5.3 psu. The ranges and ecological features of the nudibranch are very similar to the hydroid Cordylophora caspia and they co-exist everywhere, which suggests some connection. The wide geographic distribution of Tenellia adspersa is probably due to passive transportation of adults and egg masses by Cordylophora colonies on ships.
Substratum preferences	Seagrass, Artificial (e.g. metal/wood/concrete), Algae, Small boulders, Pebbles, Cobbles	Physiographic preferences	Estuary, Isolated saline water (Lagoon), Enclosed coast / Embayment
Biological zone	Lower Eulittoral, Sublittoral Fringe, Upper Infralittoral	Wave exposure	Sheltered, Very Sheltered
Tidal stream strength/Water flow	Strong (3-6 kn), Moderately Strong (1-3 kn), Weak (<1 kn)	Salinity	Variable (18-40 psu), Low (<18 psu)
Habitat Additional Information
Distribution References	Picton & Morrow, 1994, Hayward & Ryland, 1995b, Antsulevich & Starobogatov, 1991, Anonymous, 1999(s)
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Lecithotrophic, Direct Development
Reproductive Season	Insufficient information	Reproductive Location	Insufficient information
Reproductive frequency	Annual protracted	Regeneration potential	No
Life span	<1 year	Age at reproductive maturity	<1 year
Generation time	<1 year	Fecundity	25 to 50 eggs per spawn
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential 10-100m Larval settlement period Insufficient information Duration of larval stage Insufficient information
Additional Information	Tenellia adspersa has a subannual lifecycle with a short generation time of as little as 20 days when reared at 20 degrees C and 30 ppt on the hydroid Cordylophora lacustris. The animals may spawn 3 to 5 times a day with 25 to 50 eggs per spawn (Chester, 1996). The spawn consists of a short, curved, lozenge-shaped mass. The period from spawning to hatching lasts 4-5 days. The method of development varies with the environmental conditions. Metamorphosis normally takes place within the egg capsule, hatching as a juvenile. In animals that have been starved a switch to pelagic non-feeding or planktotrophic development has been observed.
Reproduction References	Chester, 1996