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External views of Phocoena sinus from near El Golfo de Santa Clara, Sonora, Gulf of California, Mexico. (A)—lateral views of specimens, top to bottom, with total lengths are: male (ITESM 850313-04- " 24 " ), 134.5 cm; female (ITESM 850313- 02- " 27 " ), 135 cm; female (ITESM 850313-01- " 26 " ), 135 cm; female (ITESM 850313- 03- " 25 " ), 70.3 cm. (B and C)—eye and lip patches and flipper stripes of specimens: male (ITESM 850313-04- " 24 " ), 134.5 cm (B); female (ITESM 850313-02- " 27 " ), 13 5 cm (c). Marks from the gill nets in which the animals were captured can be seen just anterior to the flipper of each porpoise. These linear indentations in the skin are especially clear in B and C. The pseudo-stalked barnacles, Xenobalanus globicipitis, can also be seen attached to the tip of the flipper in B.  

External views of Phocoena sinus from near El Golfo de Santa Clara, Sonora, Gulf of California, Mexico. (A)—lateral views of specimens, top to bottom, with total lengths are: male (ITESM 850313-04- " 24 " ), 134.5 cm; female (ITESM 850313- 02- " 27 " ), 135 cm; female (ITESM 850313-01- " 26 " ), 135 cm; female (ITESM 850313- 03- " 25 " ), 70.3 cm. (B and C)—eye and lip patches and flipper stripes of specimens: male (ITESM 850313-04- " 24 " ), 134.5 cm (B); female (ITESM 850313-02- " 27 " ), 13 5 cm (c). Marks from the gill nets in which the animals were captured can be seen just anterior to the flipper of each porpoise. These linear indentations in the skin are especially clear in B and C. The pseudo-stalked barnacles, Xenobalanus globicipitis, can also be seen attached to the tip of the flipper in B.  

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The vaquita, Phocoena sinus, is a porpoise in the family Phocoenidae that lives only in the Gulf of California. The external appearance of P. sinus was unknown until 13 fresh specimens were recently examined. The most obvious morphological feature distinguishing P. sinus from its two congeners is the proportionately higher dorsal fin. The most stri...

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... In contrast, the ovaries of nine adult female vaquitas taken as bycatch between February and May in 1985-1993(Brownell et al. 1986, Vidal 1995 were interpreted by Hohn et al. (1996) as indicating a 2 yr calving interval. Herein we examine photographic evidence that suggests annual calf production in vaquitas is possible, leading us to reexamine the conclusions of Hohn et al. (1996). ...
... The larger porpoise was photographed with V01F at a time when the vaquitas were in the presence of many boats, Table 1. Total length (TL) in cm, sex (F, M) and maturity (adult or immature), and dorsal fin height (DH) in cm for vaquitas necropsied by R. L. Brownell, L. Torres, and O. Vidal (Brownell et al. 1986, Vidal 1995 Under such conditions, we expect that calves will stay close to their mothers, which makes it seem likely that the larger porpoise was, indeed, the mother of V01F. The identity of the third animal observed at the start of the encounter remains unknown. ...
... From the90 endemic fish species, the vaquita marina (Phocoena sinus) a porpoise with an average length of 150cm [2] and a unique genetic background [3,4], is currently the most threatened marine mammal in the world due to anthropogenic influence [5] and chronologically; the catch of tatoaba fish, sharks and shrimps [6]. By 2008, the abundance of vaquitas was estimated to be 245 [7]; this count was reduced to60 in 2016 [8,9]. ...
... In 1986, however, the first recorded specimens were caught in a gillnet set for totoaba research. This was also the first time that fishers' common name for the porpoise, vaquita (a rare sight even to them), was properly adopted (Brownell et al. 1987). Renewed interest in vaquita was followed by bycatch monitoring programs to estimate its population size, with a first estimate of ~600 individuals. ...
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Socio-political issues are important in environmental policy outcomes but are often overlooked in conservation planning. We analyze the effects of historical social, political, and ecological contexts on conservation policy outcomes as applied to the Upper Gulf of California and Colorado River Delta Biosphere Reserve. A rushed implementation, perhaps necessary for the protection of endangered totoaba (Totoaba macdonaldi) and vaquita (Phocoena sinus), occurred with little community consultation, resulting in enduring disgruntlement among stakeholders that undermined its effectiveness. Overfishing and habitat degradation continue both inside and outside the reserve, and totoaba and vaquita remain Critically Endangered, with the latter’s population estimated at approximately 90 individuals. Marine reserves can be useful, but when top-down enforcement is unfeasible, effective environmental policy requires full recognition and integration of political history and social structures and needs, and open discussion on trade-offs when win-win situations are not possible.
... Here I attempted this independently by compiling measurements of body length and whole body weight for 1711 extant adult cetaceans, where body length and weight were measured on the same individual animal. Measurements are listed in Online Resource 4. Thirty-two genera and 59 species representing all 12 or 13 families of extant Cetacea are included (Lipotes vexillifer, possibly extinct, is not represented), with measurements drawn from Enders (1942), Wilke et al. (1953), Houck (1961), Kenyon (1961), Pilleri (1969a, 1969b), Harrison and Brownell (1971), Pilleri and Gihr (1971), Kasuya (1972), Kamiya and Yamasaki (1974), Bigg and Wolman (1975), Lockyer (1976), Tiexeira (1979), Forrester et al. (1980), Miyazaki et al. (1981), Nagorsen and Steward (1983), Omura et al. (1984), Robineau and Buffrenil (1985), Brownell et al. (1987), Viikingsson et al. (1988), André et al. (1990), Cockcroft and Ross (1990), Camphuysen et al. (2008), Mikhalev and Budylenko (2012), and a U. S. National Museum database (USNM 2014). Regression of log 10 body weight on log 10 body length for the 1711 extant individuals is shown in Fig. 3. ...
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Calibration of the Brownian diffusion model of Felsenstein indicates that phylogeny may have an influence on body length and other phenotypic measures in Cetacea for as many as 10,000 generations or about 180,000 years, which is negligible in the 35 million year history of extant Cetacea. Observations of phenotypic traits in cetacean species living today are independent of phylogeny and independent statistically. Four methods for estimating body weight in fossil cetaceans are compared: (1) median serial regression involving a set of multiple regressions of log body weight on log centrum length, width, and height for core vertebrae; (2) regression of log whole body weight on log body length for individuals; (3) regression of log whole body weight on log body length for species means; and (4) regression of log lean body weight on log body length for individuals. These yield body weight estimates for the Eocene archaeocete Dorudon atrox of 1126, 1118, 1132, and 847 kg, respectively, with consistency and applicability to partial skeletons favoring the first approach. The whole-body weight expected, Pe (in kg), for a given body length, Li (in cm), is given by log10 Pe = 2.784 • log10 Li − 4.429. Negative allometry of body weight and body length (slope 2.784 < 3.000) means that small cetaceans are shorter and more maneuverable than expected for their weight, while large cetaceans are longer and more efficient energetically than expected for their weight. Encephalization is necessarily quantified relative to a reference sample, most mammals are terrestrial, and terrestrial mammals provide a logical baseline. The encephalization residual for living terrestrial mammals as a class (ERTC), is the difference between observed log2 brain weight (Ei in g) and expected log2 brain weight (Ee in g), where the latter is estimated from body weight (Pi in g), as log2 Ee = 0.740 • log2 Pi − 4.004. ERTC is positive for brains that are larger than expected for a given body size, and negative for brains that are smaller than expected. Base-2 logarithms make the ERTC scale intuitive, in uniform units of halving or doubling. Encephalization quotients (EQ) are unsuitable for comparison because they are proportions on a non-uniform scale. Middle Eocene archaeocetes have ERTC values close to −2 (two halvings compared to expectation), while late Eocene archaeocetes have ERTC values close to −1 (one halving compared to expectation). ERTC is not known for fossil mysticetes, but living mysticetes have ERTC values averaging about −2. Oligocene-Recent odontocetes appear to have ERTC values averaging about +1 (one doubling compared to expectation) through their temporal range. Definitive interpretation of the evolution of encephalization in Cetacea will require better documentation for Oligocene–Recent mysticetes and odontocetes.
... Simultáneamente al marcado interés inmobiliario en las costas y a la crisis de la pesca de camarón sucedió la reinvención ecologista del Alto Golfo. El redescubrimiento a mediados de los ochenta de una especie de mamífero marino endémico que apenas había sido descrito treinta años atrás (Brownell 1987), fue contundente para la generación de un fuerte accionar conservacionista. La vaquita marina se convirtió en el estandarte de una nueva forma de entender el extremo norte del mar de Cortés y en la justificación para programar el porvenir de la región. ...
... Simultáneamente al marcado interés inmobiliario en las costas y a la crisis de la pesca de camarón sucedió la reinvención ecologista del Alto Golfo. El redescubrimiento a mediados de los ochenta de una especie de mamífero marino endémico que apenas había sido descrito treinta años atrás (Brownell 1987), fue contundente para la generación de un fuerte accionar conservacionista. La vaquita marina se convirtió en el estandarte de una nueva forma de entender el extremo norte del mar de Cortés y en la justificación para programar el porvenir de la región. ...
... Simultáneamente al marcado interés inmobiliario en las costas y a la crisis de la pesca de camarón sucedió la reinvención ecologista del Alto Golfo. El redescubrimiento a mediados de los ochenta de una especie de mamífero marino endémico que apenas había sido descrito treinta años atrás (Brownell 1987), fue contundente para la generación de un fuerte accionar conservacionista. La vaquita marina se convirtió en el estandarte de una nueva forma de entender el extremo norte del mar de Cortés y en la justificación para programar el porvenir de la región. ...
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La conservación de la biodiversidad en el Alto Golfo de California y la organización del trabajo en la pesca: Omisiones y sustracciones oficiales hablan de "pescadores del Alto Golfo de California que voluntariamente aceptaron renunciar" a su oficio, para dedicarse a proyectos productivos y comerciales alternativos. Sin embargo, detrás de los sujetos que los promotores de la conservación asumen como pescadores existe una división del trabajo que ha permanecido invisible. Con el actuar de organizaciones no gubernamentales conservacionistas y con el contexto de la crisis inmobiliaria y del turismo, el conflicto está teniendo repercusiones que resultan interesantes para una sociología del desarrollo.
... This is in agreement with the known spring calving season of the species (Hohn et al., 1996). Juveniles were slightly darker in color than the adults that accompanied them (as shown in Fig.1 of Brownell et al., 1987). Most of the groups observed appeared to be either milling/feeding or traveling. ...
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The vaquita (Phocoena sinus) is the most endangered species of cetacean in the world, with an estimated global population of less than 150 individuals. The species is listed as Critically Endangered by the IUCN, and is on the U.S. and Mexican endangered species lists. It is expected that the population will dwindle to extinction if management solutions (primarily the removal of gillnets from the species' range) are not implemented in the next couple of years. The lack of high-quality photographic images of living vaquitas has been a serious impediment to conservation efforts for the species. This project aimed to obtain the first such images and to evaluate the potential for using photo-identification to study the species. Twenty surveys were conducted in the northern Gulf of California between 2 and 30 October 2008. We observed 13 groups of vaquitas and several dozen high-quality images were obtained, which are currently being used for conservation and education purposes. We were also able to identify six individuals from natural markings, although two of these may not possess markings suitable for long-term identification. Based on the small sample, an estimated 24-31% of adult vaquitas possess long-term markings, and thus photo-identification appears to be a valid technique for use with this species. All photographed individuals appeared healthy, with no evidence of malnutrition, and several calves were observed. Future planned work will include long-term photo- identification studies to examine aspects of the species' life history, movements, social organization, and health status. Through these efforts we hope to increase the prospects for the species' long-term survival.
... There may never have been an abundant, widespread population . The species was not scientifically described until 1958 (Norris & McFarland 1958), with full descriptions of external morphology not available until 1987 (Brownell et al. 1987). P. sinus has the most restricted distribution of any marine mammal, with a core area of approximately 2235 km 2 in the shallow, rich waters of the upper Gulf of California, Mexico (Jaramillo-Legorreta et al. 1999) (Fig. 1). ...
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Although many studies confirm long-term small isolated populations (e.g. island endemics) commonly sustain low neutral genetic variation as a result of genetic drift, it is less clear how selection on adaptive or detrimental genes interplay with random forces. We investigated sequence variation at two major histocompatibility complex (Mhc) class II loci on a porpoise endemic to the upper Gulf of California, México (Phocoena sinus, or vaquita). Its unique declining population is estimated around 500 individuals. Single-strand conformation polymorphism analysis revealed one putative functional allele fixed at the locus DQB (n = 25). At the DRB locus, we found two presumed functional alleles (n = 29), differing by a single nonsynonymous nucleotide substitution that could increase the stability at the dimer interface of alphabeta-heterodimers on heterozygous individuals. Identical trans-specific DQB1 and DRB1 alleles were identified between P. sinus and its closest relative, the Burmeister's porpoise (Phocoena spinipinnis). Comparison with studies on four island endemic mammals suggests fixation of one allele, due to genetic drift, commonly occurs at the DQA or DQB loci (effectively neutral). Similarly, deleterious alleles of small effect are also effectively neutral and can become fixed; a high frequency of anatomical malformations on vaquita gave empirical support to this prediction. In contrast, retention of low but functional polymorphism at the DRB locus was consistent with higher selection intensity. These observations indicated natural selection could maintain (and likely also purge) some crucial alleles even in the face of strong and prolonged genetic drift and inbreeding, suggesting long-term small populations should display low inbreeding depression. Low levels of Mhc variation warn about a high susceptibility to novel pathogens and diseases in vaquita.
... 29. Lower jaw (Brownell et al. 1987, Jefferson 1988): 0 = Extends anterior to upper jaw or to same level as the upper jaw, 1 = Upper jaw extends anterior lower jaw. 30. ...
... 31. Apex of the flipper (Leatherwood and Reeves 1983, Brownell et al. 1987): 0 = Sharply pointed, 1 = Rounded at tip. 32. Dorsal fin (Jefferson and Newcomer 1993, Reeves et al. 2002): 0 = Present, large 1 = Vertical ridge (small), 2 = Absent. ...
... 33. Tubercles on dorsal fin (Leatherwood and Reeves 1983, Brownell et al. 1987): 0 = Present, 1 = Absent. 34. ...
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Prior studies of phylogenetic relationships among phocoenids based on morphology and molecular sequence data conflict and yield unresolved relationships among species. This study evaluates a comprehensive set of cranial, postcranial, and soft anatomical characters to infer interrelationships among extant species and several well-known fossil phocoenids, using two different methods to analyze polymorphic data: polymorphic coding and frequency step matrix. Our phylogenetic results confirmed phocoenid monophyly. The division of Phocoenidae into two subfamilies previously proposed was rejected, as well as the alliance of the two extinct genera Salumiphocaena and Piscolithax with Phocoena dioptrica and Phocoenoides dalli. Extinct phocoenids are basal to all extant species. We also examined the origin and distribution of porpoises within the context of this phylogenetic framework. Phocoenid phylogeny together with available geologic evidence suggests that the early history of phocoenids was centered in the North Pacific during the middle Miocene, with subsequent dispersal into the southern hemisphere in the middle Pliocene. A cooling period in the Pleistocene allowed dispersal of the southern ancestor of Phocoena sinus into the North Pacific (Gulf of California).