Meeting Abstract

P2.123  Saturday, Jan. 5  A Descriptive Study of the Cranial Morphology of Opistognathidae: Linking skull characteristics to burrow construction MILLER, L.B.*; MEHTA, R.S.; University of California, Santa Cruz; University of California, Santa Cruz leithmiller1@gmail.com

The skulls of fishes accomplish many critical functions, only one of which is capturing prey. For example, many jawfish species (Opistognathidae) are not only oral brooders but also exemplify a unique behavior that consists of lifting and manipulating large pieces of rubble to construct burrows using their jaws. Previous research of this group has been largely observational, mainly describing the burrow construction behaviors of various jawfish species. However, there has been no investigation on what cranial modifications may allow jawfish to lift large pieces of rubble with their mouths. Here, we investigate the cranial morphology of three species of shallow water rubble-dwelling jawfish: the yellow-barred jawfish, (Opistognathus sp.), the galapagos jawfish (O. galapagensis) and the giant jawfish (O. rhomaleus) to gain insight into what particular features of the skull may contribute to this interesting behavior. We used clearing and staining techniques as well as gross dissections to examine the musculoskeletal elements of the skull. We find that in all three species, jaw length comprises a significant portion of total head length and that there is very little to no jaw protrusion ability, despite the fact that there are many species that have been reported to feed on planktonic prey. We also find that jawfish species have robust lower jaws, relatively large adductor mandibulae muscles, and large oral gape dimensions, adaptations that may assist in lifting pieces of rubble with the jaws.