Robert Rush Miller

Extinctions of North American Fishes During the past Century

Abstract Extinctions of 3 genera, 27 species, and 13 subspecies of fishes from North America are documented during the past 100 years. Extinctions are recorded from all areas except northern Canada and Alaska. Regions suffering the greatest loss are the Great Lakes, Great Basin, Rio Grande, Valley of Mexico, and Parras Valley in Mexico. More than one factor contributed to the decline and extinction of 82% of the fishes. Physical habitat alteration was the most frequently cited causal factor (73%). Detrimental effects of introduced species also were cited in 68% of the extinctions. Chemical habitat alteration (including pollution) and hybridization each were cited in 38% of the extinctions, and overharvesting adversely affected 15% of the fishes. This unfortunate and unprecedented rate of loss of the fishery resource is expected to increase as more of the native fauna of North America becomes endangered or threatened.

Threatened Freshwater Fishes of the United States

Abstract Threatened, native freshwater fishes are listed for 49 of the 50 U.S. States, the first such compilation. Over 300 kinds are included in a formal classification, cross-indexed to states (Table 1), followed by state lists and the status of each fish, whether rare, endangered, depleted, or undetermined. The concern for native fishes and the important factors responsible for threats to their existence are briefly outlined. Although the lists vary from those based on extensive recent state surveys to others in which current information is sparse, publication is expected to enhance the chances for survival through protective legislation (already enacted by a number of states) and stronger concern for such natural resources.

Systematics of Gasterosteus aculeatus, with Particular Reference to Intergradation and Introgression along the Pacific Coast of North America: A Commentary on a Recent Contribution'

nized. Retention of G. a. aculeatus is favored for the fully plated Holarctic form; tentatively G. a. microcephalus is retained for the Pacific partly plated form (pending detailed comparisons), and the normally plateless southern California form is regarded as a well-marked subspecies, G. a. williamsoni, which definitely intergrades with G. a. microcephalus.

Origin and Dispersal of the Alewife, Alosa Pseudoharengus, and the Gizzard Shad, Dorosoma Cepedianum, in the Great Lakes

Abstract It is possible that the alewife is native to Lake Ontario and the gizzard shad to Lake Erie, although conclusive evidence for this is lacking. There appear to be no records of the alewife from Lake Ontario prior to 1873, after the lake had been stocked with American shad. That species may still occur in Lake Ontario occasionally. A tabular comparison of these species is given to facilitate identification. The alewife is referred to the genus Alosa (rather than Pomolobus) because no reliable characteristics are available to distinguish the species of these two groups. Wilmot recorded a herring-like fish (not the American shad) from Lake Ontario about 1837 which probably was the gizzard shad, though it may have been the alewife. The first record of gizzard shad in Lake Ontario is for 1913, but the species was reported from Lake Erie in 1848, 18 years after the completion of the first canal to connect Lake Erie and the Ohio River. It is hypothesized that the gizzard shad entered Lake Erie in pre-Col...

Classification of the Native Trouts of Arizona with the Description of a New Species, Salmo apache

A new species of trout, Salmo apache, is described from the White Mountains of eastern Arizona, in the Gila and Little Colorado River drainages. Specimens collected in 1873, 1915, 1937, and 1950, along with reliable information on trout introductions and study of collections made in the last decade, assure that certain stocks still persisting today are pure. Survival of the species has been greatly aided by the foresight of the White Mountain Apache Tribe. A second trout, Salmo gilae Miller (described from New Mexico), was also native to Arizona (as shown by 1888-1889 material from Oak Creek) but was eliminated after 1900. Salmo apache is distinguished by a set of characters involving life colors, spotting, body proportions, numbers of scales, vertebrae, and pyloric caeca, occasional presence of basibranchial teeth, and by its karyotype (2n = 56). It is compared with Salmo chrysogaster (of Mexico), S. clarki, S. aguabonita, S. gilae, and S. gairdneri, with some osteological observations included. Chromosomes show promise for helping to determine relationships in the genus Salmo, although much more data are needed. Speculations are presented on the origin of the trouts of Arizona, with information on an important Mexican fossil (Plio-Pleistocene) that may be closely related to S. chrysogaster. I conclude that the latter species represents a distinct phyletic line of Salmo, evidently the most primitive one in western North America, and that there are at least three other evolutionary lines. It is suggested that the California golden trout was derived from an ancestor (or combination of ancestral forms) that entered the Sacramento-San Joaquin Valley from the north, where it is perhaps represented today by the redband trout of McCloud River basin, California.

Karyology of the Cyprinodontoid Fishes of the Mexican Family Goodeidae

tistical package for the social sciences (2nd edition). McGraw-Hill, New York. OKERA, W. G. P.,J. D. STEVENS ANDJ. S. GUNN. 1981. Tropical sharks-fishery situation report. Proc. Symp. Northern Pelagic Fish., Darwin. 59-72. PRATT, H. L. 1979. Reproduction in the blue shark, Prionace glauca. Fish. Bull. U.S. 77:445-470. SPRINGER, V., ANDJ. A. F. GARRICK. 1964. A survey of vertebral numbers in sharks. Proc. U.S. Natl. Mus. 116:(3496):73-96.

Management of the Owens Pupfish, Cyprinodon radiosus, in Mono County, California

Abstract The Owens pupfish, Cyprinodon radiosus Miller, is restricted to Owens Valley along the eastern base of the Sierra Nevada Range of California. When it was described in 1948 it was thought to be extinct. Its depletion, rediscovery, and reestablishment in the Owens Valley Native Fish Sanctuary, a cooperative undertaking between the City of Los Angeles and the California Department of Fish and Game, are described. Two other refuges in Owens Valley are completed or under construction, and the three additional native fishes of this valley will be established in one of these. Such conservation activity reflects the growing concern of the scientific community and the public over the threat to native fishes.

DISTRIBUTION, ADAPTATION AND PROBABLE ORIGIN OF AN ALL-FEMALE FORM OF POECILIOPSIS (PISCES: POECILIIDAE) IN NORTHWESTERN MEXICO

At least five, morphologically distinct, all-female forms occur in the viviparous fish genus Poeciliopsis (Schultz, 1966; Schultz, 1969). These appear to have had a similar origin, even though in different parts of their range they are not associated with the same gonochoristic (bisexual) species of Poeciliopsis. Morphological and experimental evidence indicate that the common ancestor to all of the unisexual forms was a diploid unisexual that originated through hybridization, at which time it was endowed with its obligatory unisexuality and a disruptive meiotic mechanism. This form, termed P. monacka-lucida (Schultz, 1969) has given rise to two gynogenetic triploid populations by incorporating an additional genome from one or the other of the ancestral bisexual species involved in its origin. Two other derived forms are diploid and like P. monacka-lucida sustain themselves by a unique reproductive mechanism termed hybridogenesis (Schultz, 1969). In gynogenesis, spermatozoa are required to initiate cleavage, but paternal chromatin is not incorporated into the zygotic nucleus. Offspring of hybridogenetic organisms, on the other hand, exhibit characteristics of both parents but unisexuality is retained by excluding the entire paternal genome from functional ova in the process of oogenesis. The latter mode of reproduction, theoretically, has high adaptive value. Females that reproduce by such a mechanism have a genome which is isolated from the gene pool of the bisexual species

The Introduced Fishes of Nevada, with a History of their Introduction

Abstract At least 39 species and subspecies of fishes have been introduced into the waters of Nevada since 1873. Of these, 24 kinds are now known to occur in the state. A thorough survey of the exotic fishes has not been made, but specimens or records of introduced species have been kept in the course of rather extensive collecting of the native fish fauna from 1934 to 1943. Consequently it is believed that the number of introduced species herein enumerated approaches a complete tabulation. Some additions among the sunfishes and catfishes may be expected. The annotated list is divided into two parts: species now present in the state, and species introduced but never established. The established kinds constitute about two-thirds of the total number of known native species, but are far outnumbered by the indigenous fishes when all the local subspecies (Hubbs and Miller, in press) are included. The stocking of cutthroat trout and rainbow trout in the same creek should be discouraged since these two species h...

Middle Pliocene Cyprinid Fishes from the Bidahochi Formation, Arizona

Significant differences have been noted between fish faunas of Pliocene and Pleistocene times. Consequently, study of Pliocene fishes may be expected to contribute importantly to an understanding of the evolutionary history of the living American fish fauna. Four species of cyprinids are described from Arizona, of which 3 are new-including a new genus. A K-Ar dating of 4.1 million years establishes, along with evidence from fossil biotas (mammals and mollusks), the Middle Pliocene age of the Bidahochi formation. All 4 species are illustrated. Ptychocheilus prelucius is regarded as ancestral to the living Colorado squawfish, P. lucius; ?Gila cristifera and Evomus navaho represent extinct species and an extinct genus. Gila cf. G. robusta indicates, along with P. prelucius, that the Colorado River had, by Middle Pliocene time, attained the swift-river habitat to which the modern representatives are so admirably adapted. Absence of suckers from the Bidahochi formation may be explained on the basis that Amyzon, an early evolutionary line of the Catostomidae representing species found in lacustrine deposits, did not survive the Miocene, whereas other suckers evidently reached the area later.