Endobacterial morphotypes in nudibranch cerata tips: a SEM analysis

Table 1 Overview of endobiotic bacteria and their aggregates within the epidermic tip region of cerata from 12 nudibranch species

Nudibranch groups	Aeolidiacea								Dendronotacea			Arminiaceae
Species	Aeolidia papillosa	Berghia caerulescens	Coryphella brownii	Coryphella lineata	Coryphella verrucosa	Cuthona amoena	Facelina coronata	Flabellina pedata	Dendronotus frondosus	Doto coronata	Tritonia plebeia	Janolus cristatus
Aggregates and endobacterial morphology
Bacterial aggregates with envelope
Coccoid shaped bacteria (μm)	10/1.4^a 4/0.5	6/0.8 13/0.9 r ne/1.3 po	25/2.5		15/1.7		5/0.5	6/0.6				6/1.0
Oval-shaped bacteria (μm)		5/0.8 × 1.3 No envelope										4/0.8 × 1.6 Envelope 7/0.8 × 1.5 No envelope
Coccoid bacteria and aggregates without envelope (μm)				0.5 0.5 × 0.9 sp								0.9
Dispersed coccoid endobionts (μm)	0.8	0.9	1.2			1.4	1.0	0.7	ca 2-4 μm	1.5	1.0
Endobionts located closely to cnidocysts	+	+	+	+	+	nd.	+	+	nd	+	+	nd

Nudibranch species selected prey on cnidarian diet (exception Janolus cristatus usually feeds on bryozoan Bugula sp.). Aggregate and bacterial sizes are approximate values
nd not detected, ne not estimable, r rough surface, po polymorphic, sp spindle shaped
^aFirst number gives aggregate diameter and second refers to bacterial size, + detected

ISSN: 1438-3888