Illinois Natural History Survey - University of Illinois

Key to GRANIA (Annelida: Clitellata: Enchytraeidae) of North America, Bermuda, and the Caribbean

Jan M. Locke, Kathryn A. Coates, and Jason Ritter

University of Toronto, Zoology Department & Bermuda Biological Station for Research, Inc.


 

The marine, clitellate genus Grania Southern, 1913 is a globally prevalent group of enchytraeids within intertidal and shallow subtidal habitats. The genus seems to be more diverse in tropical and subtropical locations. Eight species have been described from eastern, coastal North America, the Caribbean and the oceanic Atlantic islands of Bermuda. Due to the rising numbers of species within the genus over the last twenty years and changes in recognized distributions, a basic, artificial, dichotomous key using anatomical characters of Grania is important for species identification. A key for species of the genus Grania from eastern North America, the Caribbean and the islands of Bermuda is presented here.

||  Introduction  ||  Recognition of Grania  ||  Glossary  ||  Systematic Comments  ||

   ||  Literature Cited & Selected References  ||  Website Index & History  ||

 


 

KEY TO SPECIES IN THE GENUS GRANIA Southern, 1913

The hierarchy of the following key is wholly artificial. Numbers in parentheses
indicate the couplet from which the current couplet was reached.

1.

A. Ventral setae occurring before clitellum....................................................….2

B. Ventral setae absent or only post-clitellar….......……..............................…..7

2. (1)

A. No glands present at spermathecal pore…....…...........................................5

B. Glands present at spermathecal ectal pore……...............................…...…..3

3. (2)

A. Statocyst present. Penial apparatus with single bulbous gland. Penial stylet absent................................................................................…Grania americana

B. Statocyst not present. Penial apparatus with anterior and posterior glands
at male pore. Penial stylet absent.....…….........................................................4

4. (3)

A. Two pair of spermathecae present in V and VI. Ventral setae in II, absent in
III to XXI-XXVII. Lateral setae absent...................Randidrilus quadrithecatus

B. One pair of spermatheca in V. Ventral setae from II. Lateral setae absent
..........................…........................................................….Randidrilus codensi

5. (2)

A. Spermathecal ectal pores dorsal. Penial apparatus a bipartite sac, stylet present.........................................................................................................…..6

B. Spermathecal ectal pores lateral. Penial apparatus bulbous, stylet absent….......................................................................................................…10

6. (5)

A. Elongate muscular modifications of vas deferens. No statocyst anterior
to the brain........................................................................Grania bermudensis

B. Muscular constrictions of vas deferens. Statocyst anterior to brain…...........
.......................................................................................................Grania hylae

7. (1)

A. Lateral, paired spermathecal pores. Penial apparatus bulbous....................8

B. Mid-dorsal, single spermathecal pore. Penial apparatus a bipartite sac........
................................................................................Grania monospermatheca

8. (7)

A. Penial stylet absent.......................................................……..Grania reducta

B. Penial stylet present................................................................………………9

9. (8)

A. Setae lacking entirely.............................................................….Grania levis

B. Setae only postclitellar......................................................Grania longiducta

10. (5)

A. Bipartite spermathecal ectal duct. Statocyst present...........Grania atlantica

B. Distinct dilation midway along spermathecal ectal duct. Statocyst absent..... ...................................................................................................Grania laxartus

 


INDEX
© Copyright 1999-2017, K.A. Coates
ALL RIGHTS RESERVED

{page update: 22 January 2017, MJW}



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