John R. Shute

Guidelines for Propagation and Translocation for Freshwater Fish Conservation

Abstract Reestablishment of locally extinct populations and augmentation of declining populations are management activities used with increasing frequency in the conservation of imperiled fishes in the United States. Unfortunately, these options were not always carefully or appropriately used in past cases, partly owing to a lack of guidelines that address scientifically-based protocols for propagation, translocation, reintroduction, and augmentation (PTRA). PTRA programs are an important management tool for the recovery of imperiled fishes when undertaken with careful planning, including everything from determining that PTRA is necessary to incorporating knowledge of life history and genetics into the PTRA plan. In addition, PTRA programs must also assemble advisory groups, obtain funding and permitting, construct and maintain propagation facilities, and raise community awareness of the program. Because such diverse skills are needed, successful PTRA programs should prepare for long-term partnerships to ...

Reproductive behavior, captive breeding, and restoration ecology of endangered fishes

Species recovery efforts generally focus on in situ actions such as habitat protection. However, captive breeding can also provide critical life history information, as well as helping supplement existing or restoring extirpated populations. We have successfully propagated nine species in captivity, including blackside dace, spotfin chubs, bloodfin darters, and boulder darters. Threatened blackside dace, Phoxinus cumberlandensis, were induced to spawn in laboratory aquaria by exposing them to milt from a reproductively mature male stoneroller, Campostoma anomalum or river chub, Nocomis micropogon. The latter are nest-building minnows, with which Phoxinus may spawn in nature. Eggs are broadcast among gravel and pebbles. Blackside dace individuals reared in captivity were used for translocation. Threatened spotfin chubs, Cyprinella monacha, fractional crevice spawners, deposited eggs in laboratory aquaria in the spaces created between stacks of ceramic tiles. Captively produced spotfin chubs were used as part of a larger stream restoration and fish reintroduction project in the Great Smoky Mountains National Park. The bloodfin darter, Etheostoma sanguifluum, was first used as a surrogate to develop techniques for spawning a closely related species, the endangered boulder darter, E. wapiti. Both darter species mated in a wedge created between two ceramic tiles. Our efforts have had variable but generally high success, with survival rates of 50–90% of eggs deposited. Captive production of nongame fishes can aid recovery of rare species or populations, aid in watershed restoration, and can help to refine water quality standards. In addition, captive breeding allows discovery of important behavioral or life history characteristics that may constrain reproduction of rare species in altered natural habitats.

Spawning and nesting behavior of the waccamaw darter,Etheostoma perlongum

SynopsisThe spawning and nesting behavior ofEtheostoma (Boleosoma) perlongum was investigated in the field and laboratory. Sexual dimorphism is highly developed in such features as genital papillae, first dorsal and paired fins, and nuptial coloration. A reproductive migration from mid-lake to shore occurs in the spring: males precede females to select nest sites under submerged sticks and other debris. The male excavates a depression beneath the submerged object. Gonad analysis indicates a single spawning season extending from March through June. Nests were found from late April to mid-June and were guarded by a single male for periods of 13 to 36 days. Males initiate courtship by lateral display, lead the female to the nest site and show the nest by inverting. The female responds by tail up, tail wag and circle; males also tail wag and circle. Spawning pairs invert, usually in unison, and orient head to head or, less often, head to tail. The female deposits eggs while holding her body in a weak ‘S’ or ‘J’ shape with the caudal peduncle held away from the spawning substrate while vibrating.

Breeding behavior and early life history of the waccamaw killifish,Fundulus waccamensis

SynopsisThe territorial, courtship and spawning behavior ofFundulus waccamensis was investigated in the field and laboratory. Spawning occurs from April to August. Sexual dimorphism is manifested through dichromatism, genitalia, morphometric differences and contact structures. In nature, nuptial males vigorously defend circular territories and court entering females by circling them, sidling, ‘J’ shaping and spawning in the sand substrate. In the aquarium, males perform eight advertisement motor patterns during courtship, of which dipping and flashing are most frequent. The female is relatively inactive, performing only two basic acts. The maximum number of mature eggs per ovary is 120. Both mature egg numbers and total egg numbers are highly correlated with standard length. Recently fertilized eggs are colorless and adhesive. The newly hatched young is well developed and relatively large in size.

Selection of sites for egg deposition and spawning dynamics in the waccamaw darter

We provided 93 experimental spawning covers for the waccamaw darter. We grouped the covers (3 sizes of slate and one of concave tile) in three arrangements at six Lake Waccamaw locations to separate the variables of water depth, distance from shore, cover density and cover type. Tag returns of marked males suggest low fidelity for nest sites. Egg production under the 3 different sizes of slate was not significantly different. Egg production under the tile was significantly less than that under the slates. Egg production was significantly higher off the undeveloped southeastern shore in 2 m of water and lowest at the shallowest location with the highest experimental cover density. The number of eggs in nest is positively correlated with male size. We conclude that medium size slate covers placed in a linear arrangement in 2 m of water on a mixed sand bottom result in the highest egg production for the waccamaw darter.

Captive Propagation, Reproductive Biology, and Early Life History of the Diamond Darter (Crystallaria cincotta)

Abstract Reproductive biology and early life history data are critical for the conservation and management of rare fishes. During 2008–2012 a captive propagation study was conducted on the Diamond Darter, Crystallaria cincotta, a rare species with a single extant population in the lower Elk River, West Virginia. Water temperatures during spawning ranged from 11.1–23.3 C. Females and males spawned with quick vibrations, burying eggs in fine sand in relatively swift clean depositional areas. Egg size was 1.8–1.9 mm, and embryos developed within 7 to 11 d. Diamond Darters were 6.7–7.2 mm total length (TL) at hatch. Larvae ranged from 9.0–11.0 mm TL following a 5–10 d period of yolk sac absorption. Larvae had relatively large mouth gapes and teeth and were provided brine shrimp Artemia sp., Ceriodaphnia dubia neonates, marine Brachionus rotifers, and powdered foods (50–400 µm) but did not appear to feed in captivity, except for one observation of larval cannibalization. Larvae survived for a maximum of 10 d. To increase larval survival and reduce the possibility of cannibalism, other alternative food sources are needed during captive propagation.

Pelagic larval duration predicts extinction risk in a freshwater fish clade

Pelagic larval duration (PLD) can influence evolutionary processes ranging from dispersal to extinction in aquatic organisms. Using estimates of PLD obtained from species of North American darters (Percidae: Etheostomatinae), we demonstrate that this freshwater fish clade exhibits surprising variation in PLD. Comparative analyses provide some evidence that higher stream gradients favour the evolution of shorter PLD. Additionally, similar to patterns in the marine fossil record in which lower PLD is associated with greater extinction probability, we found a reduced PLD in darter lineages was evolutionarily associated with extinction risk. Understanding the causes and consequences of PLD length could lead to better management and conservation of organisms in our increasingly imperiled aquatic environments.

Spawning and Captive Propagation of Blackside Dace, Chrosomus cumberlandensis

Abstract Chrosomus cumberlandensis (Blackside Dace) is a federally protected stream fish endemic to the upper Cumberland River drainage of Kentucky and Tennessee. Captive propagation of the species has been conducted in only one previous study. Here we report new findings from spawning and rearing the species for the past three years, 2011–2013, at the Conservation Fisheries, Inc. (CFI) facility in Knoxville, TN. Brood stock (n = 80 adults) were collected in 2011–2012 from Big Lick Branch in Pulaski County, KY Spawning at the CFI facility occurred in April and May of each year when CFI water temperatures were between 16 and 21 °C. We compare CFI spawning dates and temperatures to those measured in a 2006 field study. We also provide video footage of spawning behavior, which conformed to that previously described in the literature. Per capita production of fry (i.e., number of juveniles reared per breeding adult) in 2012 was more than twice that achieved in the previous study. We progressively reduced the presence of (and cues from) other fish species in 2011, 2012, and 2013, with the eventual achievement of having Blackside Dace spawn completely independent from any heterospecific cues. Our results collectively increase the capacity to propagate Blackside Dace in captivity to support ongoing recovery efforts for this threatened species.

Captive Propagation, Reproductive Biology, and Early Life History of Etheostoma wapiti (Boulder Darter), E. vulneratum (Wounded Darter), and E. maculatum (Spotted Darter)

Abstract Reproductive biology and early life-history data are important for understanding the ecology of fishes. In 2008, we conducted captive propagation studies on 3 species of darters of the subgenus Nothonotus: Etheostoma wapiti (Boulder Darter), E. vulneratum (Wounded Darter), and E. maculatum (Spotted Darter). The length of spawning period and associated range of water temperatures for the Wounded Darter exceeded that of the Spotted Darter and Boulder Darter. The mean number of eggs produced per female was lowest for Boulder Darter and highest in the Wounded Darter. The Boulder Darter had the highest percent of eggs hatched, the lowest percent larval to juvenile stage survivorship, and the lowest mean number of juveniles produced per female. Egg diameters at deposition and prior to hatch were smallest for the Spotted Darter. If reproductive biology and early lifehistory information from captive fishes represent that of wild populations, then the data obtained during this study are relevant to development and implementation of conservation and management plans for these closely related darter species.