In a span of days, a 70-foot fin whale was filmed in the Salish Sea off Vancouver Island, a caiman exceeding four metres was freed from a fishing net in Colombia’s Magdalena Medio, and researchers described a spider in Ecuador that mimics a fungus lethal to its own kind. Separately, Costa Rican scientists reported genetic evidence for a fourth species of ghost shark, pending comparative analysis with specimens from Peru and Chile. The cluster of encounters, while unrelated, draws attention to both the slow recovery of once-depleted species and the gaps that remain in cataloguing biodiversity.

The fin whale, the second-largest animal on Earth, has been documented only a handful of times in the Strait of Juan de Fuca over the past decade. Whale-watching operators attribute the increasing presence of large cetaceans to conservation measures implemented since the closure of British Columbia’s last commercial whaling station in 1967. In Colombia, biologist David Echeverri of the regional environmental authority Cornare said the large caiman—though startling to fishermen—is a sign that habitat restoration and reforestation efforts are yielding results. The animal was untangled and released at a distant site.

In Ecuador’s Llanganates-Sangay Corridor, an international team formally described Taczanowskia waska, the first spider known to mimic a parasitic fungus of the genus Gibellula that infects and kills spiders. The discovery, published in Zootaxa, originated from a photograph posted on the citizen-science platform iNaturalist that observers initially mistook for a mushroom. The spider remains motionless on the underside of leaves, a behaviour that reinforces its disguise. Researchers from the Leibniz Institute for the Analysis of Biodiversity Change say the finding expands understanding of mimicry as a survival strategy in poorly studied rainforest taxa.

Off Costa Rica’s Pacific coast, specimens of a ghost shark with a shorter snout, darker colouration, and a longer dorsal spine showed no reproductive contact with the three known species, according to Arturo Angulo Sibaja of the University of Costa Rica. However, similarities to individuals collected near Peru and Chile mean the team is conducting further morphological and genetic comparisons before confirming a new species. Ghost sharks, or chimaeras, are cartilaginous fish that diverged from sharks nearly 400 million years ago and inhabit depths of up to 2,600 metres. The next milestone for both the ghost shark and the fungus-mimicking spider will be follow-up studies that clarify their ecological roles and taxonomic status.