Lloyd Findley

Records of gray whales (Eschrichtius robustus) at and near their two known calving sites in the Gulf of California (Sea of Cortés), México, are reviewed up to 1995. The sites of Tojahui/Yavaros (Sonora) and Bahía Santa María (Sinaloa) represented the most distant calving grounds regularly visited by the species. Prior observations (mainly in the 1950s and 1960s) revealed relatively small but seasonally consistent numbers of whales, with maximum counts, including calves, of 30 individuals at Bahía Santa María in 1954, and 17-19 at Tojahui/Yavaros in 1955, 1963 and 1971. Observations (initiated in 1979) as well as interviews with longtime local residents and fishermen, document a decline in numbers and occupancy times of whales, especially cow/calf pairs, visiting these sites. In contrast, 19th century whaling records indicate that many more gray whales were found seasonally along these coasts. The recent decline, leading to the apparent disappearance, is likely to be due to human-ind...

Plate tectonics and sediment processes control regional continental shelf topography. We examine the genetic consequences of how glacial-associated sea-level change interacted with variable near-shore topography since the last glaciation. We reconstructed the size and distribution of areas suitable for tidal estuary formation from the Last Glacial Maximum, ~20 thousand years ago, to present from San Francisco, California, USA (~38 °N) to Reforma, Sinaloa, Mexico (~25 °N). We assessed range-wide genetic structure and diversity of three co-distributed tidal estuarine fishes (California Killifish, Shadow Goby, Longjaw Mudsucker) along ~4,600 km using mitochondrial control region and cytB sequence, and 16–20 microsatellite loci from a total of 524 individuals. Results show that glacial-associated sea-level change limited estuarine habitat to few, widely separated refugia at glacial lowstand, and present-day genetic clades were sourced from specific refugia. Habitat increased during postglacial sea-level rise and refugial populations admixed in newly formed habitats. Continental shelves with active tectonics and/or low sediment supply were steep and hosted fewer, smaller refugia with more genetically differentiated populations than on broader shelves. Approximate Bayesian computation favored the refuge-recolonization scenarios from habitat models over isolation by distance and seaway alternatives, indicating isolation at lowstand is a major diversification mechanism among estuarine (and perhaps other) coastal species. Because sea-level change is a global phenomenon, we suggest this top-down physical control of extirpation-isolation-recolonization may be an important driver of genetic diversification in coastal taxa inhabiting other topographically complex coasts globally during the Mid- to Late Pleistocene and deeper timescales

The Gulf of California supports a rich elasmobranch fauna, with more than 85 documented species. However, environmental alteration (e.g., damming of the Colorado River, marine pollution, coastal development) and years of unregulated fishery exploitation have resulted in substantial changes to the marine fauna of this region, including considerable declines in populations of several elasmobranch species. Apparent changes in elasmobranch faunal composition will be treated qualitatively (based on a synthesis of available information) because detailed historic records are not available. An updated list of all documented elasmobranch species will be provided, and single occurrences and recent absences will be discussed. Patterns of taxonomic diversity will be compared to those of other comparable subtropical regions. In addition, trends in species composition and diversity of demersal, nearshore elasmobranchs will be quantitatively assessed based on the results of comprehensive, year-rou...

In 2013, the seventh edition of the Common and Scientific Names of Fishes from the United States, Canada, and Mexico was published. Major changes include the capitalization of English common names, the addition of French common names for each species found in Canada, and the recognition of occurrences in the Arctic Ocean as separate from the Atlantic and Pacific oceans. Some scientific names have changed with advancing knowledge of the phylogenetic relationships and most changes are straightforward, although a few are not unambiguous due to conflicting conclusions among researchers. The list has grown from 570 freshwater and marine entries in 1948 list (primarily better known sport, commercial, and forage fishes), to 1,892 species in 1960, 2,131 in 1970, 2,268 in 1980, and 2,428 species in 1991. The 2004 list increased to 3,694 with the addition of the Mexican fauna. The 2013 list includes 3,875 species. The 2013 list will be used to explore the diversity of North American freshwate...

A new species of seven-spined goby of the genus Chriolepis is described from four specimens from four widely separate western Atlantic localities (Little Bahama Bank; off southwestern Florida; Tobago Island; and northeastern Colombia) from depths ranging from 62 to 138 m. The species is distinct from all other western Atlantic species currently assigned to the genus Chriolepis in having a fully scaled body, the first two dorsal-fin spines greatly elongated in both sexes, especially so in females, and two anal-fin pterygiophores inserted anterior to the first haemal spine. It differs from members of the similar genus Varicus in having branched pelvic-fins rays, a longer fifth pelvic-fin ray and more numerous meristic elements. It closely resembles Chriolepis atrimelum, known from a similar depth at Isla del Coco in the eastern Pacific Ocean. 

A new species of seven-spined goby of the genus Chriolepis is described from five specimens collected from the continental shelf of the northeastern Gulf of Mexico and Atlantic Ocean off South Carolina in depths of ca 54 to 110 m. The "Platform Goby", Chriolepis prolata, is distinguishable from all other western Atlantic species currently assigned to the genus Chriolepis and the morphologically similar genus Varicus in having pelvic-fin rays one through four branched, the fifth (innermost) pelvic-fin ray unbranched and relatively long (longer than the second ray to longer than all other pelvic-fin rays); most lateral body scales ctenoid, extending anteriorly in a wedge to a level anterior to the first dorsal-fin insertion or nearly to the pectoral-fin axil, with two or more rows of small cycloid scales extending anteriorly to near the pectoral-fin axil, cycloid scales along the bases of the dorsal and anal fins, and no scales on the belly; and the first two anal-fin pteryg...

Low-frequency vocalizations were recorded from fin whales, Balaenoptera physalus, in the Gulf of California, Mexico, during three cruises. In March 1985, recorded 20-Hz pulses were in sequences of regular 9-s interpulse intervals. In August 1987, nearly all were in sequences of doublets with alternating 5- and 18-s interpulse intervals. No 20-Hz pulse sequences of any kind were detected in February 1987. The typical pulse modulated from 42 to 20 Hz and its median duration was 0.7 s (1985 data). Most other fin whale sounds were also short tonal pulses averaging 82, 56, and 68 Hz, respectively, for the three cruises; 89% were modulated in frequency, mostly downward. Compared to Atlantic and Pacific Ocean regions, Gulf of California 20-Hz pulses were unique in terms of frequency modulation, interpulse sound levels, and temporal patterns. Fin whales in the Gulf may represent a regional stock revealed by their sound characteristics, a phenomenon previously shown for humpback whales, birds, and fish. Regional differences in fin whale sounds were found in comparisons of Atlantic and Pacific locations.