Eugene G. Maurakis

Spawning Behaviors in the Bluehead Chub, Nocomis Leptocephalus, River Chub, N. Micropogon and Central Stoneroller, Campostoma Anomalum

Abstract Spawning behaviors were filmed and observed in the nest-building minnows, the bluehead chub, Nocomis leptocephalus, and river chub, N. micropogon. Analysis of videotapes exposed previously unreported behaviors (e.g., female retroflexure) and a precise sequence of male-female interactions that coordinated a successful spawn. Reproductive behaviors were classified into six sequential categories (interim, approach, alignment, run, clasp, dissociation) to facilitate interspecific comparisons. The most conspicuous differences between species involved the intensity of the females retroflexure and the males spawning clasp (strong in N. leptocephalus vs. weak in N. micropogon) and reproductive behaviors of subordinate males. In N. leptocephalus, subordinate males spawned concurrently and independently of the resident male over a communal nest, whereas in N. micropogon a subordinate acted like a satellite male and stole spawns from the nest-building male. In addition, heterogeneric spawning clasps involving a male and female N. leptocephalus and a male central stoneroller, Campostoma anomalum, are newly described.

Reproductive-behavioral Phylogenetics of Nocomis Species-groups

-Descriptions of nest construction and reproductive behaviors of Nocomis species, identified from field observations and laboratory analysis of video tapes, are used to evaluate previous species-group designations (biguttatus, leptocephalus and micropogon) based on morphology. Three behavioral synapomorphies, the three-stage process of nest construction (excavating a concavity, forming a platform and building a mound), pit fanning of spawning troughs and pits with the anal fin of nesting males, and circle swims (reported for the first time) support the monophyly of Nocomis. Nocomis biguttatus and N. leptocephalus form a monophyletic group based on two behavioral synapomorphies (spawning pit excavation and covering eggs after spawning).

Freshwater fish habitat science and management in Greece

Objectives are to (1) characterize the current status of and threats to freshwater fish habitats, native fishes, and fisheries in Greece; (2) canvas the states and priorities of fisheries science, legislation, and regulations for freshwater habitats and their fishes/fisheries; (3) indicate priority gaps in freshwater fish habitat management; and (4) comment on planning and managing strategies for freshwater aquatic resources and fishes in Greece. Freshwater fishes total 126 species (58 % endemic), 19 of which are introductions. Inland fishery production (about 700 t in 1999) has steadily decreased (due to overfishing, habitat alteration, and pollution) for the past 40 years while marine fisheries have increased from ∼12000 to 30000 t in 30 years (1964-1994). Population declines and extirpation of fish species and their habitats have been related to dam construction and operation, stream channelization, canalization, pollution, and stream desiccation, a result of water abstraction for crop irrigation and diversion of river and stream waters for potable waters supplies of urban and rural areas. Published information on habitat requirements (i.e., spawning habitat, spawning behavior, nursery areas, foraging ranges, vegetative cover, and migration) of freshwater fishes in Greece is limited. Absence of coordination among ministries and an increased market-based economy have resulted in low conservation priorities and investments for freshwater environs. Conservation programs and action plans have been implemented in Greece only recently for two endemic fish species ( Pungitius hellenicus and Ladigesocypris ghigii ) compared to 14 for other vertebrate species. Regardless of environmental statues and presidential decrees since 1970, there is no current established national action plan to improve and integrate aquatic environments and natural habitat management in a growing market-based economic strategic plan. Recommendations for the creation of an integrated, national action plan that incorporates environmental costs of protecting freshwater aquatic habitats and fish communities in sustainable economic policies and goals of Greece, an European fringe country experiencing significant competition in the international marketplace are presented.

Microstructure of Attachment Mechanisms of Newly Hatched Larvae of Four Cyprinid Species with Comments on Terminology

An adhesive organ is a prominent, protruding mucus secreting gland that is used by newly hatched tadpoles and larvae of some fishes to attach to aquatic vegetation. The objective of this research is to test the hypothesis that newly hatched cyprinid larvae of Hybognathus hankinsoni, Notemigonus crysoleucas, Cyprinus carpio and Gila atraria contain cephalic adhesive organs. Newly hatched larvae of Semotilus atromaculatus, which do not attach to submerged aquatic vegetation, were used as the control. SEM examination of newly hatched larvae indicate there were no adhesive organs on the control species (S. atromaculatus) or test species (H. hankinsoni, N. crysoleucas, C. carpio and G. atraria). Rather, newly hatched larvae of test species contain a localized highly modified epidermis (i.e., primarily on the ventral cephalic and anterioventral yolk sac surfaces of H. hankinsoni, N. crysoleucas, C. carpio, and G. atraria, and sometimes on dorsal cephalic epidermal cells of H. hankinsoni, C. carpio, and G. atraria). This modified epidermis is composed of epidermal cells with unculi-like projections, elevated microridges at peripheries of epidermal cells, and mucus from apical pores of goblet cells that probably are responsible for attachment of test species to substrates. We hypothesize that the unculi-like projections at centers of epidermal cells in newly hatched larval test cyprinids are true unculi. There is a need to define and clarify the meanings of words and phrases (i.e., cement gland, cement gland apparatus, cement gland-like structure, casquette, temporary adhesive glands, adhesive apparatus, adhesive gland, adhesive organ, attachment organ, and glue secretion and adhesion) for structures used by newly hatched larvae to attach to substrates. Definitions should be based on homologies, crucial in phylogenetic reconstructions of species relationships and in identifying developmental homologues of cells, tissues, glands, and organs that have been described as mechanisms for attachment by newly hatched larvae of various species to substrates. We proposed the phrase “attachment mechanism” as a broad definition for the ways in which newly hatched larvae attach and adhere to substrates during early development. This broad definition, however, should be modified to define specific methods of attachment (e.g. attachment mechanism of unculi, elevated epidermal microridges, and mucus) to assist in defining homologies.