Page 1

LIMAX

VALENTIANUS

FERUSSAC

(MOLLUSCA:LIMACIDAE) NEW TO

SUFFOLK

I . J. KILLEEN

A m o n g s t a b a t c h of molluscs collected by Eric P a r s o n s f r o m his east Ipswich g a r d e n (TM189439) in S e p t e m b e r 1986 w e r e two slugs of u n c e r t a i n identity. S u b s e q u e n t e x a m i n a t i o n of t h e distal genitalia s h o w e d t h e m to b e Limax (Lehmannia) valentianus Ferussac. T w o f u r t h e r s p e c i m e n s w e r e collected by J i m P o p e f r o m a horticultural g r e e n h o u s e at L e v i n g t o n (TM239399) in N o v e m b e r 1986. L. valentianus is a s o u t h e r n E u r o p e a n species, native to t h e I b e r i a n peninsula, b u t it is n o w widely s p r e a d by m a n in m a n y p a r t s of the world. In north-west E u r o p e it has b e e n r e c o r d e d f r o m g r e e n h o u s e s in most countries, including several in t h e British Isles. T h e Ipswich discovery is of interest in t h a t t h e s p e c i m e n s w e r e f o u n d in an o p e n site. In r e c e n t years t h e r e have b e e n two o t h e r o p e n site r e c o r d s f r o m m a i n l a n d Britain: Sandy, B e d s . ( E . B. R a n d s , 1985) a n d L u t o n , B e d s . ( D . W . G u n t r i p , 1986), and two f r o m Ireland ( D u b l i n a n d Belfast). It s e e m s likely t h a t s p e c i m e n s (or eggs) a r e being i n t r o d u c e d f r o m g a r d e n c e n t r e s / g r e e n h o u s e s on plant and soil material. H o w e v e r , d u e to the cold w i n t e r s , t h e r e must be s o m e d o u b t over w h e t h e r L. valentianus can establish itself in o p e n habitats in this c o u n t r y . L. valentianus is not reliably s e p a r a t e d f r o m t h e similar native species Limax (Lehmannia) marginatus M Ăź l l e r on e x t e r n a l characteristics alone. L. marginatus is typically an a r b o r e a l w o o d l a n d species, h o w e v e r , it has b e e n f o u n d in t h r e e S u f f o l k g a r d e n s . T h e r e a r e also several o t h e r similar species in E u r o p e , which m a y well turn u p in this c o u n t r y . Dissection is t h e only reliable m e t h o d of identification. E x t e r n a l l y L. valentianus is highly variable. T h e slug is m e d i u m sized, usually 5 - 7 c m e x t e n d e d a n d with a grey-violet body. T h e specimens f r o m Ipswich w e r e very d a r k and m o t t l e d and t h e Levington s p e c i m e n s w e r e a pale yellowish-buff colour. A l t h o u g h b o d y colour m a y vary, t h e r e is usually always a pair of dark lateral b a n d s high u p on t h e b o d y , a n d a pair of lyre-shaped b a n d s on t h e m a n t l e . T h e m u c u s is colourless, very watery and p r o d u c e d copiously. I w o u l d w e l c o m e any s p e c i m e n s with the characteristics described. I am g r a t e f u l to Miss Stella Davies ( C r o y d o n ) and M r . A d r i a n Norris ( L e e d s M u s e u m ) for confirming the identity of t h e Ipswich and Levington s p e c i m e n s respectively, and to D r . Michael K e r n e y ( B M N H ) for providing m e with details of t h e o t h e r British records. Ian J. Killeen, 163 H i g h R o a d W e s t , Felixstowe, IP119BD, Suffolk

Trans. Suffolk

Nat. Soc. 23

Limax valentianus Ferussac (Mollusea: Limacidae) new to Suffolk  

Killeen, I. J.

Read more
Read more
Similar to
Popular now
Just for you