In 1883 a baleen whale stranded at ‘baie de Bassora’ (Basrah Bay), in the Chat-el-Arab river delta, Iraq, at the northwestern corner of the Persian/Arabian Gulf. Gervais obtained the complete specimen for the national museum in Paris (MNHN), and described it as a new humpback whale species Megaptera indica H.-P. Gervais, 1883. The authors studied the incomplete and slightly damaged holotype skull, measured and estimated craniometrics, and concluded that M. indica is a junior synonym of Megaptera novaeangliae (Borowski, 1781). No postcranial bones were found. Importantly, two cranial features suggest that M. indica nests between Atlantic humpback whales and other large Balaenopteridae. Megaptera novaeangliae has the widest skull index, i.e. breadth skull at squamosals relative to condylobasal length (57–66.9%, n=8), higher than M. indica which scored 54.9%, and considerably higher than other Balaenopteridae. Also the ratio of the width of skull at postorbitals (frontale) versus rostrum width at base in M. indica is smaller and barely overlaps with Atlantic humpback whales (n=4), again suggesting taxonomic significance. Gervais also reported several postcranial differences, presently unverifiably. Cranial findings support subspecific status, Megaptera novaeangliae indica (H.-P. Gervais, 1883), proposed also by Amaral et al. (submitted) for the Arabian Sea (cum Persian/Arabian Gulf) humpback whale population, based on mtDNA control region analysis.The reported pachyostosis in the Iraqi whale is suggested a possible example of phenotypic plasticity, an adaptation to the unusually high-salinity, high-density habitat of the Gulf, as to reduce buoyancy and avoid insolation.

The first inventory of cetacean diversity in coastal waters of the Congo River Estuary, Democratic Republic of the Congo, was obtained between May 2021 and April 2022, through incidental sightings (n=17) reported mainly by artisanal fishers and direct observations of bycatches at fish landing sites. Confirmed records include five odontocete ...

We present the first evidence of lethal interspecific aggressive behavior against Burmeister’s porpoise Phocoena spinipinnis , in a non-predatory context, and the first indications of such behavior in a cetacean from Chilean waters. Two cases, both adult males, are described. Analysis of the fresh tooth rakes, specifically the inter-rake distance, points to common bottlenose dolphin Tursiops truncatus as aggressor. Interdental distances measured on skulls allowed us to exclude Orcinus orca, Globicephala melas, Lagenorhynchus obscurus and Pseudorca crassidens. Evidence of severe blunt trauma, including extensive subdermal hematomas, rupture of pleura and extrusion of lung parenchyma, underscores the level of violent aggression. The reason is unknown but Tursiops truncatus is well-documented to occasionally harass and kill harbour porpoises Phocoena phocoena in the Northern Hemisphere. Considering the scarce information available on the biology and behavioral ecology of Burmeister’s porpoises in Chile and elsewhere, we recommend more systematic field research. Also, as to help formulate effective management measures that can mitigate the main threat for this species in Chile (as in Peru), i.e. fisheries interactions. In Chile, P. spinipinnis is classified as Data Deficient (D.S. N°06-2017), so its real conservation status is unknown.

Knowledge on the biology of the coastal spotted dolphin Stenella attenuata graffmani from western South America, one of the least studied delphinid taxa, is summarized for the first time. Information was obtained largely opportunistically during field research targeting other species or during whale watching. Life history is discussed including distribution (Colombia, Ecuador, Peru, Chile), external morphology and pigmentation, cranial characteristics, reproduction and growth, feeding, behavioral ecology, parasites and pathology, but also genetic diversity, population structure and fisheries interactions. As a (sub)tropical dolphin its habitual austral range is the Piura Department, northern Peru, but under El Niño conditions it can reach Lima Province (Cerro Azul at 13°02’S). No evidence was found for Chile. The coastal subspecies is heavily spotted and substantially bigger, as reflected in body length and all cranial measurements. Condylobasal length, mandibular ramus length and height do not even overlap with the offshore S. a. attenuata morph. Phylogenetic analysis of the hypervariable part of mtDNA control region, revealed Ecuadorian coastal spotted dolphins to be distributed across seven different clades, with most belonging to the three largest clades, while only one haplotype was found in each of the remaining four. This pattern suggests a complex evolutionary history, possibly indicating substructures within the population or an ongoing evolutionary process. The presence of haplotypes in multiple clades may reflect high genetic diversity, likely influenced by dolphin migration between nearby geographic areas, facilitating haplotype exchange and contributing to the observed distribution.

Few reports exist on the pathologies of the northern bottlenose whale (Hyperoodon ampullatus) and other Ziphiidae. We here describe a large exostosis in the right pterygoid bone of adult female H. ampullatus ANSP-3004 that stranded on the US Atlantic coast in 1867. Images of the skull and 14 cranial measurements were examined and compared with two ‘normal’ adult female H. ampullatus specimens. Surface scans of ANSP-3004 were made with a Faro Design Arm 1.0 scanner at 75µm resolution. The form, structure and width (15.9 cm) of the right pterygoid were found to be abnormal. Its distal extremity was curved in labial direction while its proximal extremity was deformed by a large, bulbous exostosis of 14.3 x 12.5 cm that partially obstructed the right nasal passage. Lytic lesions in the posterior end of the exostosis exposed deep resorption lacunae. The left pterygoid was thin (3.4 cm) and laterally displaced. No diagnosis was possible for lack of histological examination but the osteopathy was consistent with osteoma, a benign bone tumor commonly seen on the jaws and nasal sinuses of bovines, phylogenetical relatives of Cetacea. The partial nasal passage obstruction may have affected respiration to some degree, but since the female was lactating, general fitness appeared stable.

The notion that ‘ S tock- G’ humpback whales off western South America are primarily deep oceanic migrators is poorly supported. We document ed 6 6 land-based sightings from Pucusana, Lima Sur : 18 incidental ( 2002 – 2023) and 48 dedicated sightings during the northbound winter migration (June-July 2023 ), covering respectively 38 and 105 individual whales, despite a mean daily observer effort of only 5 8.7 min . Estimated distance s from shore ranged 20 – 7,000 m (mean= 2,729 m) at dep ths 25–99 m, while 50% migrate d at < 2,500 m (median) from shore. Several groups skirt ed the coastline from headland to headland. Of five southbound migrating group s , four included a n adult with neonate; no northbound groups enclosed a neonate. Two cases of single juvenile/subadult whales moving multidirectionally and closely associated with large seabird feeding frenzies, were considered foraging also. In 2023, 94% of all northbound near shore sightings occurred from 14 June-11 July, signalling the maximum threat period for interactions with coastal fisheries off metropolitan Lima . If migration is temporally and spatially predictable, effective mitigating measures should be feasible.