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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.
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A bstract
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. Th...
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Citations
... The vaquita has been called the "panda of the sea" because of its eye markings (Sea Shepherd 2024b; Figure 1). It was first described in 1958 based solely on skeletons (Norris and McFarland 1958) and was later morphologically described from individuals accidentally drowned in gillnets set to catch sharks and conduct totoaba surveys (Brownell et al. 1987). As few as 35 vaquita specimens incidentally caught and studied between 1985 and 1991 account for most of the rarely documented evidence of fishing mortality on the vaquita (Vidal 1995). ...
The world's smallest porpoise—the vaquita (Phocoena sinus)—is on the brink of extinction. Endemic to the upper Gulf of California, it has dwindled to fewer than 19 individuals in 2023. The primary source of mortality is drowning in gillnets set for totoaba (a giant croaker fish). Our review of the past 50 years of efforts to simultaneously attain conservation goals for the vaquita and economic and social goals for the fisheries concludes that they have consistently failed to meet the lowest expectations of any stakeholders. The time has therefore come to recognise that the only solution to this problem is to make an immediate and definitive decision: either preserve the vaquita or bolster sustainable fishing in the upper Gulf—and accept the associated social, economic, and political costs of either choice.
... All confirmed records to date have been north of a line connecting Puertecitos (Baja California) and Puerto Peñasco (Sonora), Upper Gulf of California, Mexico. These include incidental catches and beached specimens (e.g., Brownell, 1983Brownell, , 1986Brownell et al., 1987;Turk-Boyer & Silber, 1990;Vidal, 1991Vidal, , 1995, photographs (Jefferson et al., 2009) and sightings (e.g., Silber, 1990a;Silber & Norris, 1991;Gerrodette et al., 1995Gerrodette et al., , 2011Jaramillo-Legorreta et al., 1999Taylor et al., 2017Taylor et al., , 2019Thomas et al., 2017;Rojas-Bracho, Gulland et al., 2019;Rojas-Bracho, Booth et al., 2019;Rojas-Bracho, Brusca et al., 2019;Rojas-Bracho et al., 2022). Circles and squares indicate the approximate location and number of specimens observed or beach cast. ...
... What is known about the external morphology of this, the world's smallest cetacean, is limited to only three published studies. Brownell et al. (1987) described the external morphology and coloration based on 13 fresh specimens collected in 1985; Hohn et al. (1996) compared the total length, body mass, and maximum girth growth curves of 56 male and female vaquitas; and Torre et al. (2014) evaluated the sexual dimorphism and isometric and/or allometric growth of the same 56 specimens examined by Hohn et al. (1996). ...
... The shapes of the eye patch, lip patch, and flipper stripe all vary slightly among individuals. Additional details of the color pattern are given by Brownell et al. (1987). ...
... Al igual que los delfines, las marsopas pertenecen al grupo de los odontocetos (Figura 72), es decir, los cetáceos con dientes. Esta especie se describió con base en dos cráneos encontrados en las playas de San Felipe, B.C. en 1950 y 1951 (Norris y MacFarland, 1958) y su morfología se describió hasta 1987 con base en unos ejemplares recién muertos en redes agalleras en el Alto Golfo de California (Brownell et al., 1987;Vidal et al., 1999). Las vaquitas llegan a medir hasta 1.5 m de longitud y las hembras son ligeramente más grandes que los machos. ...
... Trailing edge of dorsal fin, pectoral flippers, and mostly tail flukes (Calman, 1920;Barnard, 1924;Cornwall, 1927;Cornwall, 1928;Pope, 1958;Caldwell et al., 1971;Devaraj and Bennet, 1974;Bryden, 1976;Rice, 1978;Greenwood et al., 1979;Bane and Zullo, 1980;Spivey, 1980;Raga et al., 1983b;Ross, 1984;Raga and Sanpera, 1986;Brownell et al., 1987;Mead and Potter, 1990;Rajaguru and Shantha, 1992;Van Waerebeek et al., 1993;Watson et al., 1994;Jefferson et al., 1995;Reyes and Van Waerebeek, 1995;Araki et al., 1997;Orams and Schuetze, 1998;Rittmaster et al., 1999;Vidal et al., 1999;Barros and Stolen, 2001;Parsons et al., 2001;Resendes et al., 2002;Berland et al., 2003;Di Beneditto and Ramos, 2004;Palacios et al., 2004;Kane et al., 2008;Bearzi and Patonai, 2010;Best and Meÿer, 2010;Carvalho et al., 2010;Ribeiro et al., 2010;Foote et al., 2011;Karaa et al., 2011;Martıń et al., 2011;Oliveira et al., 2011;Rosso et al., 2011;Dıáz-Aguirre et al., 2012;Gonzaĺez et al., 2012;Ólafsdóttir and Shinn, 2013;Towers et al., 2013;Whitehead et al., 2014;Dıáz-Gamboa, 2015;Kim and Sohn, 2016;Methion and Dıáz Loṕez, 2019;Pacheco et al., 2019;Herr et al., 2020;Matthews et al., 2020;Siciliano et al., 2020;Visser et al., 2020;Flach et al., 2021); also reported on the head (Samaras, 1989;Engel, 1994) and on a facial lesion (Alves-Motta et al., 2020). ...
Each individual cetacean is an ecosystem itself, potentially harboring a great variety of animals that travel with it. Despite being often despised or overlooked, many of these epizoites have been proven to be suitable bio-indicators of their cetacean hosts, informing on health status, social interactions, migration patterns, population structure or phylogeography. Moreover, epizoites are advantageous over internal parasites in that many of them can be detected by direct observation (e.g., boat surveys), thus no capture or dissection of cetaceans are necessary. Previous reviews of epizoites of cetaceans have focused on specific geographical areas, cetacean species or epibiotic taxa, but fall short to include the increasing number of records and scientific findings about these animals. Here we present an updated review of all records of associations between cetaceans and their epibiotic fauna (i.e., commensals, ecto- or mesoparasites, and mutualists). We gathered nearly 500 publications and found a total of 58 facultative or obligate epibiotic taxa from 11 orders of arthropods, vertebrates, cnidarians, and a nematode that are associated to the external surface of 66 cetacean species around the globe. We also provide information on the use as an indicator species in the literature, if any, and about other relevant traits, such as geographic range, host specificity, genetic data, and life-cycle. We encourage researchers, not only to provide quantitative data (i.e., prevalence, abundance) on the epizoites they find on cetaceans, but also to inform on their absence. The inferences drawn from epizoites can greatly benefit conservation plans of both cetaceans and their epizoites.
... 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. ...
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. ...
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. ...
