Moll. Res. 17: 3-20 (1996). 
Comparative study on gill morphology of gastropods from 
Moreton Bay, Queensland 
Richard H.M. Eertman! 
Department of Zoology, University of Queensland 
Brisbane, Queensland 4072 
! Present address: Netherlands Institute of Ecology, Centre for Estuarine and Coastal Ecology, 
Vierstraat 28, 4401 EA Yerseke, The Netherlands. 
Key words: molluscs, ctenidia, SEM/LM 
Abstract 
This paper reports the gill morphology of seven common gastropods from Moreton Bay, 
southeastern Queensland, to test the level of difference in gill structure between major 
taxa. The investigated species include representatives of the clades Patellogastropoda, 
Neritimorpha and Vetigastropda as well as representatives of the more 'advanced' 
Caenogastropoda. Examination by SEM and LM revealed that the external gill structure 
of the investigated caenogastropods (including Planaxis sulcatus, Littoraria articulata, 
Bembicium auratum and Morula marginalba) shows basic uniformity. The gill filaments 
are composed of a clearly defined ridge and an extended sheet of non-ciliated cells. The 
gill filaments of these species differ in the shape of the filaments (corrugated, triangular 
or rounded) and the presence of secretory cells. The gills of the limpet Patelloida mimula 
and neritid Nerita chameleon, representatives of the clades Patellogastropoda and 
Neritimorpha respectively, are both triangularly shaped, but differ by the presence of 
paddle shaped cilia in the former species and secretory cells in the latter. The gill 
morphology of the vetigastropod trochid Austrocochlea constricta, characterized by blade 
shaped filaments covered with nodules and a striped pattern of ciliated cells, showed the 
least similarities with the other investigated species. 
Introduction 
Gills are the principal organs of respiratory gas exchange in molluscs, and additionally perform a 
trophic function in most bivalves and some gastropods. Where primary gills (ctenidia) have been 
lost, secondary gills have evolved in some molluscan groups from modifications of the mantle 
surface (Yonge, 1952). Although the histological structure of gastropod gills has been well described 
(Hyman, 1967; Voltzow, 1994), the number of studies on gastropod gill morphology is very limited. 
A few papers have been published on the ultrastructure of ctenidia of bivalves (Nakao, 1975; 
Porvaznik et al., 1979; Fisher and Hand, 1984; Giere, 1985 and Le Pennec et al, 1988), while 
Schipp ег al. (1979) have dealt with the ctenidia of the cephalopod Sepia officialis. Russell-Hunter 
(1988) described the functional morphology of the ctenidia of chitons, but did not detail the 
ultrastructure of the gill filaments. Recently, however, Fischer et al. (1990) have presented a detailed 
SEM/TEM account of the gills of Chiton olivaceus. The few species studied in these papers have 
little in common as they belong to widely separated molluscan classes. The only ultrastructural 
Studies on gastropod gills dealt with the secondary gills of the opisthobranchs Phyllidia pulitzeri, 
Archidoris pseudoargus and Peltodoris atromaculata (Wägele, 1984; Jonas, 1986), the pulmonate 
Siphonaria capensis (De Villiers and Hodgson, 1987) and the patellogastropod Patella vulgata 
(Nuwayhid et al., 1978). These species belong to different gastropod clades and, surprisingly, 
literature on ‘prosobranch’ gill morphology is lacking. 
