Currently, my research focuses on several projects that explore different theoretical issues. My primary research area consists largely of laboratory studies on the monogamous convict cichlid fish (Archocentrus nigrofasciatus) and field studies on several species of pupfish (Cyprinodon) and beaugregory damselfish (Stegastes leucostictus).
Students in my lab are involved in a variety of projects using the convict cichlid and these include fight tactics, mate choice, pair formation, and the functions of courtship. I continue to emphasize the parental division of roles. I am particularly interested in the causation of sex-typical parental roles (e.g., females remain with the offspring while males defend the territory), especially when both parents are both able to perform the same roles. I am also examining the initiation and the resolution of role disagreements.
I have begun a long term project on the mating strategies of Texas pupfish (Cyprinodon elegans and C. bovinus). Thus far we have uncovered three male mating tactics and we are in the process of linking the appearance of these tactics to their costs and benefits. We are also examining female pupfish behavior. Females of these species seem to mate randomly and promiscuously, although we have evidence that females of some species do possess an inherent mate preference. We are now attempting to describe this promiscuity, determine the possible benefits derived from it, and relate it to the multiple male tactics.
My research program on the coral reef beaugregory damselfish (Stegastes leucostictus) has focused on the effects of breeding site quality on both courtship and defense decisions. I have recently restarted my research at the Discovery Bay Marine laboratory where I am examining how males deal with mistakes in predicting their future reproductive success.
Along with Amber Rice, assistant professor of Biological Sciences at Lehigh University, and Paul Samollow from Texas A&M University, Matthew Draud (department of biology at Long Island University, NY), I have been looking at the population genetics and behavioral ecology of the common damselfish in Barbados and Jamaica.
Some recent publications
Gagliardi-Seeley, J., Leese, J., Santangelo, N. & Itzkowitz, M. 2009. Female Convict Cichlids (Archocentrus nigrofasciatum) based their mate choice on both malesize and fighting ability. Journal of Ethology. 27:249-254
Snekser, J. & Itzkowitz, M. 2009.Sex differences in offspring retrieval behavior in the convict cichlid. Ethology. 115: 457–464.
Leese, J, Wilson, H., Ganim, A., & Itzkowitz, M. 2010. Effects of reversed size-assortative mating on spawning success in the monogamous convict cichlid, Amatitlania nigrofasciatus. Ethology, Ecology, & Evolution. 22: 95–100.
Snekser, J., Santangelo, N., Nyby, J. & Itzkowitz. M. 2011. Sex differences in biparental care as offspring develop: a field study of convict cichlids (Amatitlania siquia). Environmental Biology of Fishes. 91: 15-25.
VanBreukelen, N. A. & Itzkowitz, M. 2011. Mate removal leads to increase parental defence in free-ranging convict cichlids. Animal Behaviour. 82: 1023-1026.
Gumm, J., Snekser, J. & Itzkowitz, M. 2008. Conservation and conflict between endangered desert fishes. Biology Letters Royal Society 4:655-658.
Gumm, J., Snekser, J., Leese, J. M., Little, K.,Leese, J.,Imhoff, V.E.,Westrick, B. & Itzkowitz, M. 2011. Management of interactions between endangered species using habitat restoration. Biological Conservation. 144:2171-2176
Snekser, J., Leese, J., Gamin, A., & Itzkowitz, M. 2009. Aggression and courtship on different quality territories: Correlated behaviors, but not a syndrome. Behavioral Ecology. 209:124-130.
Leese, J., Snekser, J., Ganim, A. & Itzkowitz, M.2009. Assessment and decision making in a Caribbean damselfish: nest site quality influences prioritization of courtship and brood defense. Biology Letters Royal Society. 5:188-190.
Leese, J., Snekser, J. & Itzkowitz, M. 2010. Interactions of natural and sexual selection: damselfish prioritize brood defense with male-male competition or courtship. Behaviour. 147:37 – 52.
Gumm, J.,van Breukelen, N. A., Draud, M & Itzkowitz, M. 2010. Interactions between inter- and Intrasexual selection in the beaugregory damselfish (Stegastes leucostictus). Ethology Ecology and Evolution. 22:133-142.
Leiser, J., Little, K., & Itzkowitz, M. 2010. Mate sampling in a natural population of Pecos gambusia, Gambusia nobilis. Western North American Naturalist. 70:283-289
My primary research explores how biparental convict cichlids (Amatitlania siquia) can influence the development and behavior of their offspring through both their life experiences prior to reproduction, and their interactions with their young during the parental care period. My work focuses on three primary questions: 1) What effects do parents have on the development and behavior of their offspring before, during, and after the parental care period? 2) Are two parents more effective than one when it comes to manipulating their offspring's antipredator behavior in the presence of a threat? 3) Is one sex more effective than the other at manipulating their offspring's antipredator behavior in the presence of a threat? During the extended parental care period, parents accompany their free-swimming fry while they forage and move around the environment. For this to be successful, parents must be able to influence the immediate behavior of their offspring in order to keep them away from potential threats. When parents are alarmed they will "call" their offspring, causing the shoal to tighten, descend closer to the substrate and move towards their parents. Although both parents are capable of performing all parental care duties, there are differences in the parental roles of each sex, with females typically spending more time in direct contact with the offspring than males. This makes it possible that one sex may be more effective at alerting their offspring when a threat is present than the other. Another component of parental care in this system may be to prepare offspring for independence by teaching them about the environment that they are born into. As humans we can relate to this scenario because as parents, we recognize that we may not always be around to help our children, so we must prepare them the best we can for life on their own. Although I have found evidence that offspring are capable of learning from their parents, it is unknown if both parents are necessary, or equally effective when it comes to teaching. Finally, there is growing evidence that unpredictable environmental conditions can lead to the manifestation of transgenerational effects that alter offspring phenotype in ways that allow them to better survive. Therefore I am also investigating how predation related cues present within the maternal environment, prior to reproduction, can affect offspring antipredator phenotype.
I am also involved in research aimed at conserving and understanding the behavior of the endangered Leon Springs pupfish (Cyprinodon bovinus), a desert fish that is geographically restricted to a single spring system in west Texas. The conservation of this species poses a unique problem because, not only do they face breeding habitat loss, but they also co-occur with a known egg predator that is also endangered, the Pecos gambusia (Gambusia nobilis). Conservation efforts have included renovating their natural habitat in order to provide additional breeding area, and decrease negative interspecific interactions, and the release of captive bred Leon Springs pupfish back into the wild in order to expand the range of the species. The efficacy of these strategies continue to be monitored and, based on the behavior, population growth, and habitat use of the wild and captive bred fish, appear to be a success.
My current research focuses on the various factors controlling female mate choice and promiscuity in the Sheepshead Minnow (Cyprindon variegatus). In my first aim, I intend to decipher whether male-biased sex ratios influence the female promiscuity. My second aim examines how females assess and value potential mates, and whether these qualities are preferred among all female C. variegatus. For my third aim, I intend to understand the effect of male intrasexual behavior on female mate choice and promiscuity.
I am a behavioral ecologist focusing on monogamy and parental care behaviors. My model system is the convict cichlid (Amatitlania siquia), a monogamous, biparental cichlid fish that engages in prolonged periods of offspring care. My specific interests in this species are whether or not conflicts between members of monogamous pairs will lead to the dissolving of a pair bond and whether or not conflicts can be resolved. I am also interest in how endocrine states within this species may contribute to conflict and resolution, and whether parental care behaviors will be affected as a result. I hope this research will shed more light on how investment of both parents may contribute to the functionality of a pair bond and whether or not pair bonds can be maintained. My work with cichlids also encompasses cultural transmission of information between individuals, specifically how parents communicate information to their offspring. I have investigated this form of communication by subjecting adult cichlids to associative learning conditions, where they recognize novel predator odors as threatening when paired with natural alarm cues from conspecifics. Offspring of monogamous pairs are then observed responding to predator odor in the presence of their conditioned parents and individually to determine how parents may pass on information about their environment in order to ensure offspring survival and how that information is retained.
I am also interested in species conservation and have engaged in several projects involving a highly endangered species, the Leon Springs Pupfish (Cyprinodon bovinus). This species is threatened due to both limiting breeding habitat as well as egg predation from a sympatric, endangered species, the Pecos Gambusia (Gambusia nobilis). In order to increase habitat availability, I have helped contribute to the construction of several pools adjacent to the natural habitat in order to promote increased breeding opportunities for C. bovinus and to minimize species overlap with G. nobilis. My research has investigated how habitat renovation has affected these conservation issues by observing how territoriality affects the density of G. nobilis in and around C. bovinus territories. I have also contributed to a comprehensive study of how C. bovinus utilize natural and constructed habitats, both behaviorally and ecologically, in order to determine how future renovation projects should be directed. These studies have also investigated comparisons between both endemic and captive-raised C. bovinus in order to determine whether reintroduction of species is a viable conservation strategy. Recently, I have been overseeing a project designed to provide more information about this topic. Using the closely related Sheepshead Minnow (Cyprinodon variegatus), we have established several artificial habitats with populations of varying sex ratios to determine how territoriality and mating opportunities are affected. We are also determining how parentage of offspring is affected by using microsattelite markers to identify what proportion of males in each population sire offspring and how territoriality may or may not contribute to mating opportunities. This research may provide us with more information about how to manage species reintroduction and ensure population growth within this system.