Laboratory for the Study of Microscopic Invertebrate Diversity

Dr. Rick Hochberg

Assistant Professor of Zoology 

Department of Biological Sciences
University of Massachusetts Lowell
One University Avenue
Lowell, MA 01854 USA

Tel.: +01-(978) 934-2885
Fax.:+01-(978) 934-3044
E-mail: Rick_Hochberg@uml.edu

Research interests:

This laboratory is dedicated to the study of the invertebrate metazoa, i.e., all multicellular animals without back bones. While research on any group of invertebrates is welcome, the laboratory is mainly focused on the anatomy and functional morphology of the microscopic and often cryptic fauna of interstitial and planktonic environments. These micrometazoans are some of the smallest and most abundant animals on the planet, yet are surprisingly understudied and largely unknown relative to to the more familiar macrofauna. Many animals are less than 1 mm in body length, and some are even as small as 0.08 mm or less! Consequently, these invertebrates are often overlooked in most studies of local and regional biodiversity. With this in mind, the primary role of this laboratory is to promote a greater understanding of these Lilliputian animals beyond their recognition as anatomical oddities and ecological curiosities – to overlook such wonderful animals would be to ignore some of the most diverse metazoans on the planet, not to mention the peculiarities of body plan organization that exist only among the microscopic fauna, and are therefore entirely absent from the larger benthic, nectic and terrestrial invertebrates.

 

Members of these phyla also represent some of the smallest animals on the planet, and may therefore provide us unique insights into the limitations that size plays in the structure and function of various cells, tissues and organ systems. Relevant questions about size constraints include:

  • What are the lowers limits to muscle size and function? Does small muscle size impose specific constraints on muscle cell physiology, i.e., do tiny muscles function identical to larger muscles, or have they changed in some unique way (e.g., sarcomere ultrastructure, modifications of synaptic input) that alters their function?
  • Do extremely small neurons have the same chemical diversity as larger neurons? Have changes in cell size placed contraints on the amount or type of machinery that is available for synthesizing structural proteins and neurotransmitters?
  • Does smaller body size place constraints on the diversity of sensory devices, or do individual neurons in tiny animals have a greater range of sensory modalities relative to larger animals with more neurons?

Current research projects:

Current research is focused on the ecology, functional morphogy, neurobiology, and systematics of three major taxa – Gastrotricha, Platyhelminthes, and Rotifera – with a dabble into Mollusca (interstitial Aplacophora and Opisthobranchia), Cnidaria, and other phyla. The miniscule size of these animals generally means that microtomy and advanced microscopical techniques are required to observe their behavior, dissect their anatomy, and interpret their functional roles in the environment. Current methods and technologies employed in my laboratory (and associated laboratories) include the following: cyto- and immunohistochemistry, widefield epifluorescence and confocal laser scanning microscopy, scanning and transmission electron microscopy, and digital imaging (still and video imaging, 3D visualization, deconvolution).

Academic History:

My academic career began at Humboldt State University back in 1989 where I majored in Marine Biology. After receiving my B.S. in 1993, I worked for an environmental toxicology lab for a year before returning to HSU to get my M.A. in Biology. My research focused on the ecomorphology of interstitial gastrotrichs, and it was during these years (1995-1998) that I decided to focus my research on meiobenthic invertebrates. I went on to get m Ph.D. (1998-2002) at the University of New Hampshire, where I studied the Comparative Morphology and Evolution of the Gastrotrich Muscular System. This research was a natural extension of my earlier studies at HSU and broaded my experience in taxonomy, functional morphology and evolution - my advisor, Dr. Marian Litvaitis, was an invaluable resource during this time. One year prior to receiving my Ph.D., I was awarded a postdoctoral position at the Queensland Museum in Brisbane, Australia where I worked in the systematics laboratory of Dr. Lester RG Cannon. The Australian research focused on the alpha taxonomy of free-living, interstitial, flatworms of eastern Australia, both marine and freshwater, from northern Queensland to southern New South Wales. My time in Australia (2001-2003) provided me valuable experience in flatworm taxonomy (Typhloplanoids, Dalyellioids) and further diversified my interest in interstitial invertebrates. From there, I received a postdoctoral fellowship at the Smithsonian Marine Station in Fort Pierce, Florida, where I focused on the ecology, functional morphology and evolution of several different invertebrates including gastrotrichs, rotifers, flatworms, and molluscs. Both the staff and facilities at the Smithsonian Marine Station were wonderful and one of the highlights of my postdoctoral career. I encourage all graduate students to consider a applying for a fellowship at SMS, or any of the laboratories associated with the Smithsonian Institution. The scientists, staff and facilities are in my opinion the best in the world. In 2005, I was offered a position as Assistant Professor of Biology at the University of Massachusetts Lowell, MA. Here, I continue my research on a wide variety of invertebrates, and educate and train students about invertebrate ecology and diversity using the latest techniques and technologies. I also retain my ties with the Smithsonian Institution as a Research Associate, which affords me the opportunity to work at the Smithsonian Marine Station in Fort Pierce, Florida and the Smithsonian Tropical Research Institute (STRI) in Bocas del Toro, Panama.

STRI Group Photo - 2007 - Photo by Chip Clark (Smithsonian Institution)

 
 

Publications:

Hochberg, R. 2008. Gastrotricha of Bocas del Toro, Panama: A preliminary report. Meiofauna Marina. Accepted.

S. H. Zébazé Togouet, T. Njine, N. Kemka, M. Nola, S. Foto Menbohan,W. Koste, C. Boutin and R. Hochberg. 2007. Spatio-temporal changes in the abundance of the populations of the gastrotrich community in a shallow lake of tropical Africa. Limnologica 37: 311-322.

Hochberg, R. & Ablak Gurbuz, O. Comparative morphology of the somatic musculature in species of Hexarthra and Polyarthra (Rotifera): Its function in appendage movement and escape behavior. Zoologischer Anzeiger. In Press.

Hochberg, R. Comparative immunohistochemistry of the gastrotrich cerebral ganglion: An analysis of FMRFamide-like immunoreactivity in Neodasys cirritus (Chaetonotida), Xenodasys riedli and Turbanella sp. (Macrodasyida). Zoomorphology. In Press.

Hochberg, R. The topology of the nervous system of Notommata copeus (Rotifera: Mononogonta) revealed with anti-FMRFamide, -SCPb, and -Serotonin Immunohistochemistry Invertebrate Biology 126(3): 247-256.

Hochberg, R. & Ablak Gurbuz, O. 2007. Functional morphology of somatic muscles and anterolateral setae in Filinia novazealandiae Shiel and Sanoamuang, 1993 (Rotifera). Zoologiscer Anzeiger 246: 11-22. See the Cover.

Hochberg, R. Serotonin-like immunoreactivity in the central and peripheral nervous systems of the interstitial acochlidean Asperspina sp (Opisthobranchia). Biological Bulletin 213: 33-54. See the Cover.

Hochberg, R.  2006. On the serotonergic nervous system of two planktonic rotifers, Conochilus coenobasis and C. dossuarius (Monogononta, Flosculariacea, Conochilidae). Zoologischer Anzeiger 245: 53-62.

Hochberg, R. 2005. First record of Polymerurus (Gastrotricha, Chaetonotida) from Australia with the description of a new species from Queensland and an ultrastructural description of the cuticle in specimens of P. nodicadus. Invertebrate Biology 124:119-130.

Hochberg, R. 2005. Musculature of the primitive gastrotrich Neodasys (Chaetonotida): functional adaptations to the interstitial environment and phylogenetic significance. Marine Biology 146: 315-323.

Hochberg, R. 2004. A new genus and subfamily of Typhloplanidae (Platyhelminthes, Rhabdocoela) from Australia with a cladistic analysis of subfamily relationships. Journal of Natural History 38: 925-937.

Hochberg, R. 2004. Reproductive anatomy of Prognathorhynchus busheki (Platyhelminthes, Kalyptorhynchia) revealed by confocal laser scanning microscopy. Meiofauna Marina 13: 29-36.

Hochberg, R. 2004. Smithsoniarhynches, a new genus of marine interstitial schizorhynch (Platyhelminthes, Kalyptorhynchia) from Mosquito Lagoon and Indian River Lagoon, Florida, USA. J. Marine Biological Association of the United Kingdom 85: 1-6.

Hochberg, R. 2003. Two new species of Dactylopodola (Gastrotricha, Macrodasyida) from the islands of eastern Australia. Meiofauna Marina 12: 37-46.

Hochberg, R. & Cannon, L.R.G. 2003. Magnetia queenslandica, a new genus and new species of typhloplanid flatworm (Platyhelminthes, Rhabdocoela) from Magnetic Island in north Queensland, Australia. Raffles Bulletin of Zoology 51: 1-6.

Hochberg, R. & Litavitis, M.K. 2003. Organization of muscles in Chaetonotida Paucitubulatina (Gastrotricha). Meiofauna Marina 12: 47-58.

Hochberg, R. & Litvaitis, M. K. 2003. Ultrastructural and immunohistochemical observations on the nervous system of three macrodasyidan gastrotrichs. Acta Zoologica 84: 171-178.

Hochberg, R. 2002. A special form of sensory cilia in Lepidodermella squamata (Gastrotricha,Chaetonotida). Ophelia 55: 137-139.

Hochberg, R. 2002. Two new species of Pseudostomella (Gastrotricha) with scaled triancres from Australia. New Zealand Journal of Marine & Freshwater Research 36(3): 571-579.

Hochberg, R. 2002. Two new species of Turbanellidae (Gastrotricha, Macrodasyida) from Eastern Australia. New Zealand J. of Marine & Freshwater Research 36(2): 311-319.

Hochberg, R. & Cannon, L.R.G. 2002. Two new freshwater rhabdocoels, Austradalyellia and Haplodidymos n. gen. (Platyhelminthes) from Queensland, Australia. Zootaxa 44:1-15.

Hochberg, R. & Cannon, L.R. 2001. A new species of Gieysztoria (Platyhelminthes; Rhabdocoela; Dalyelliidae) from a freshwater lake in Queensland, Australia. Zootaxa 11:1-8.

Hochberg, R. & Litvaitis, M.K. 2001. A muscular double-helix in Gastrotricha. Zoologischer Anzeiger 240: 59-66.

Hochberg, R. & Litvaitis, M.K. 2001. Functional morphology of muscles in Tetranchyroderma papii (Gastrotricha). Zoomorphology 121: 37-43.

Hochberg, R. & Litvaitis, M.K. 2001. Macrodasyida (Gastrotricha): A cladistic analysis of morphology. Invertebrate Biology 120: 124-135.

Hochberg, R. & Litvaitis, M.K. 2001. The musculature of Dactylopodola baltica and other macrodasyidan gastrotrichs in a functional and phylogenetic perspective. Zoologica Scripta 30: 325-336.

Hochberg, R. & Litvaitis, M.K. 2001. The musculature of Draculicteria tessalata: Implications for the evolution of dorso-ventral muscles in Gastrotricha. Hydrobiologia 452: 155-161.

Hochberg, R. & Litvaitis, M.K. 2000. Functional morphology of the muscles in Philodina sp. (Rotifera: Bdelloidea). Hydrobiologia 432: 57-64.

Hochberg, R. & Litvaitis, M.K. 2000. Hexamethyldisilazane for scanning electron microscopy of Gastrotricha. Biotechnic and Histochemistry 75: 41-44.

Hochberg, R.  & Litvaitis, M.K. 2000. Phylogeny of Gastrotricha: A morphology-based framework of gastrotrich relationships. Biological Bulletin 198: 299-305 (characters, Excel matrix)

Hochberg, R. 1999. Spatiotemporal size-class distribution of Turbanella mustela (Gastrotricha: Macrodasyida) on a northern California beach and its effect on tidal suspension. Pacific Science 216: 50-60.

Hochberg, R.  1998. Post-embryonic growth and morphological variability in Turbanella mustela (Gastrotricha: Macrodasyida). Journal of Morphology 237: 116-127.

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