Naticid drilling predation on gastropod assemblages across the K–T boundary in Rajahmundry, India: New evidence for escalation hypothesis

Predation is an important process in modern oceans and in the evolutionary history of marine ecosystems. Consequently, it has been hypothesized that shelled prey modified their ornamentation in response to predation. However, bivalve ornamentation has also been argued to be important in maintaining a stable life position in the sediment and in burrowing. To test whether concentric ribs were effective against drilling by carnivorous gastropods, we examined drill hole position and completeness for four Cenozoic bivalve species that differ in rib strength (Astarte radiata, A. goldfussi, Lirophora glyptocyma, and L. latilirata). The percentage of drill holes located between the ribs increases with increasing rib strength, whereas the percentage of drill holes on top of ribs decreases. This result suggests that gastropods select the drill hole site more effectively as rib strength increases, thereby saving time and energy, and that natural selection favors gastropods that select drill hole sites betwe...

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Shell ornamentation as a likely exaptation: evidence from predatory drilling on Cenozoic bivalves

Subaerial naticid gastropod drilling predation by Natica tigrina on the intertidal molluscan community of Chandipur, Eastern Coast of India

Although common, confamilial naticid predation intensity was not very high in the geological record. Here, we gathered modern confamilial predation data from the Indian coasts and showed that confamilial naticid predation on a naticid species, Natica gualteriana, is exceptionally high at Chandipur, one of our studied areas. We studied the different aspects of confamilial predation from the Indian coasts and showed that the predators in Chandipur were highly efficient as evident from high drilling frequency (DF), site stereotypy and low prey effectiveness. Unusually high DF on N. gualteriana may be attributed to its new arrival in Chandipur where it faced competitive elimination through predation by sympatric naticid predators. Reports of failed invasion are rare. Natica gualteriana is a small invader and therefore its invasion success is threatened by resident populations of large species that extensively drill on young individuals of N. gualteriana just to break the bottleneck of their own offspring from...

A note on exceptionally high confamilial naticid drilling frequency on Natica gualteriana from the Indian subcontinent

Gastropod drilling predation in the fossil record is prevalent and has been documented by many workers; however, vivid documentation of confamilial naticid predation is poor. Here, data compiled from previously published sources, supplemented by unpublished museum collections, document different aspects of naticid confamilial predation (NCP) in a temporal-latitudinal context. Confamilial drilling frequency (DF) showed a Cretaceous low, a small rise to a stable plateau in the Eocene, followed by a peak in the Oligocene, and finally a drop to a stable level from the Miocene to the Holocene. The stepwise rise in DF is comparable with the overall history of drilling predation. However, the temporal increase in DF was visible only in the mid-latitudes, while in other latitudes, no temporal trend was observed. The frequency of failed attack has always been very low. In comparison, a decrease in prey effectiveness (PE) was observed in the Neogene relative to the Cretaceous and Paleocene–Eocene intervals. In case of site selectivity, either apertural or abapertural sites were targeted until the Oligocene, and subsequently became more random. Some of these trends may be biased based on insufficient site selectivity data as well as uneven sampling from different latitudes representing different time intervals. More data on quantification of predation intensities along with the behavioral aspects of NCP are required to properly document other aspects of this interaction.

https://bioone.org/journals/palaios/volume-32/issue-5/palo.2016.050/NATICID-CONFAMILIAL-DRILLING-PREDATION-THROUGH-TIME/10.2110/palo.2016.050.pdf

Naticid confamilial drilling predation through time

Traces of predation by drilling gastropods and peeling crabs provide important insights about predator-prey interaction in ecological as well as evolutionary times. Predation on turritelline gastropods, in this context, has been frequently discussed in literature. Here, we have estimated the intensity of predation (both drilling and peeling) on Recent turritelline gastropods from the Indian subcontinent, which has been underrepresented in previous studies. Our samples include our own collections from several Indian coasts as well as a vast collection which was locked in the archive of the Zoological Survey of India (ZSI) in Kolkata for the past 150 years. It includes samples from different parts of the Indian subcontinent as well as from many other countries. Drilling frequency (DF) of Indian turritelline species is low compared to average values of global data. We suggest that this is mainly because most of the Indian species are larger (> 4 cm) than species living elsewhere. Smaller species show higher DF and lower values of peeling frequency. Size selectivity of drill holes shows both intra- and interspecific variation. Shell thickness and ornamentation appear to be antipredatory in nature.We have compared our results with a revised global database. Distribution of intensity of predation shows latitudinal variation where both drilling and peeling frequencies increase towards the tropics.

https://bioone.org/journals/malacologia/volume-56/issue-1&2/040.056.0211/Predation-on-Recent-Turritelline-Gastropods-from-the-Indian-Subcontinent-and/10.4002/040.056.0211.pdf

Gopal Paul

Papers

Predation on Recent Turritelline Gastropods from the Indian Subcontinent and Comparison with a Revised Global Database