Feeding and digestion periodicity of Manila clam Ruditapes philippinarum in natural intertidal and subtidal zones estimated from the morphological condition of the crystalline style

2020 ◽  
Vol 86 (4) ◽  
pp. 361-371
Author(s):  
Shouji Houki ◽  
Tomohiko Kawamura

ABSTRACT Feeding periodicities and rhythms of suspension-feeding bivalves in coastal waters are closely related to diel and tidal cyclic environmental changes, such as food availability and predation risk. Although such feeding periodicities of bivalves are important for understanding how their feeding strategies adapt to localized habitats, the feeding periodicity in bivalves in the field remains to be clarified, especially in infaunal species. The present study focused on the morphological condition of the crystalline style as an indicator of the feeding activity of the infaunal bivalve Manila clam, Ruditapes philippinarum, and estimated their feeding periodicity in the field. First, the effects of feeding (siphon-extending) behaviour, food and the light/dark cycle on the condition of the crystalline style (defined based on its morphology and hardness) were investigated in the laboratory. Results of the ordered logistic models and model selection showed that clams extending their siphons kept their crystalline styles hard. Furthermore, the effects of the light/dark cycle and tidal phase on the condition of the crystalline style were investigated in natural intertidal and subtidal zones and assessed using the results of the ordered logistic models. In the intertidal zone, the effect of the tidal phase was significant, whereas the effect of the light/dark cycle was not, and feeding was estimated to be active at ebb and flood tides, when the density of food particles was likely to be high. On the other hand, in the subtidal zone, the results of the model selection were not clear because of significant effects of interactions between the light/dark cycle and tidal phase. However, when the interactions were removed from the models, the effect of the light/dark cycle was significant, and feeding was estimated to be active at night when the predation risk from visual predators would be relatively low. These results confirm that R. philippinarum possesses behavioural plasticity in feeding periodicity, which is adaptable to both intertidal and subtidal zones.

2011 ◽  
Vol 34 (8) ◽  
pp. 1190-1197
Author(s):  
Xi-wu YAN ◽  
Yue-huan ZHANG ◽  
Huan-qiang SUN ◽  
Zhong-ming HUO ◽  
Xin SUN ◽  
...  

2017 ◽  
Vol 52 (4) ◽  
pp. 202-205 ◽  
Author(s):  
Hyun-Sil Kang ◽  
Hyun-Sung Yang ◽  
Kimberly S. Reece ◽  
Young-Ghan Cho ◽  
Hye-Mi Lee ◽  
...  

2021 ◽  
Vol 152 ◽  
pp. 106484
Author(s):  
Ilaria Bernardini ◽  
Valerio Matozzo ◽  
Sara Valsecchi ◽  
Luca Peruzza ◽  
Giulia Dalla Rovere ◽  
...  

Hydrobiologia ◽  
2009 ◽  
Vol 630 (1) ◽  
pp. 139-148 ◽  
Author(s):  
C. Dang ◽  
X. de Montaudouin ◽  
J. Bald ◽  
F. Jude ◽  
N. Raymond ◽  
...  

2017 ◽  
Vol 98 (7) ◽  
pp. 1645-1657 ◽  
Author(s):  
Paula Moura ◽  
Paulo Vasconcelos ◽  
Fábio Pereira ◽  
Paula Chainho ◽  
José Lino Costa ◽  
...  

The present study aimed to describe the reproductive cycle and estimate the size at sexual maturity of the Manila clam (Ruditapes philippinarum) in the Tagus Estuary (Portugal). Specimens were collected monthly from September 2013 to December 2015 during fishing surveys using bivalve dredges. The gametogenic cycle was described in detail using gonad histology and monitored throughout the study period by the monthly variation in the frequency of gonad maturation stages, mean gonadal index and mean oocyte diameter. This invasive population of R. philippinarum displayed synchronous gonadal development between sexes, with ripening occurring mainly in April and May followed by an extensive spawning period until November–December. Individuals reached the size at first sexual maturity at 29.4 mm in shell length (i.e. before 1 year old). Furthermore, the reproductive strategy, dynamics and potential were compared between the invasive R. philippinarum and the native congeneric carpet shell clam (Ruditapes decussatus). Overall, the data gathered in this study constitutes valuable baseline information to propose conservation strategies and implement management measures to minimize the harmful impacts caused by this invasive species on local ecosystems and native biodiversity, particularly over populations of autochthonous bivalves.


2018 ◽  
Vol 36 (5) ◽  
pp. 1688-1696 ◽  
Author(s):  
Zhongming Huo ◽  
Xiangyu Meng ◽  
Rbbani Md.Golam ◽  
Weinan Cao ◽  
Qidi Wu ◽  
...  

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