These are the questions readers raise most often, grouped by what they concern: how the site works, how to read the numbers, and what the profiles do and do not claim. Each answer points to the page where the topic is treated in full.
Where do the figures on the profiles come from?
Every measurement is drawn from published scientific and government sources, such as the IUCN Red List, NOAA Fisheries, the Smithsonian and FishBase. Each profile lists the sources it relied on at the bottom of the page, and the full registry is on the sources page. The site does not conduct original field research, so it is best read as a carefully cited starting point that leads back to the institutions doing the work.
Why do some measurements appear as ranges?
Animals vary by sex, age, region and individual, and the most extreme figures are often the least documented. A range reflects what the literature supports, and a typical value is given where one exists. A note beside each figure explains how it was obtained and where the evidence is thin.
Why are units shown in feet and pounds first?
The site is written for an American audience, so measurements are shown in feet, miles and pounds first with metric values alongside. Everything is stored in metric and converted at display time, so the two always agree.
What does the conservation status code mean?
The code is the global category assigned by the IUCN Red List, such as LC for Least Concern or EN for Endangered, with the year of the assessment and the population trend beside it. A status describes extinction risk under defined criteria and is not a count of animals. The guide on reading conservation status explains the categories and why Data Deficient is not the same as safe.
Why is the orca listed as Data Deficient?
Orcas around the world differ so much in diet, genetics, calls and appearance that several forms may turn out to be separate species. Until the taxonomy is settled, the global assessment cannot give a meaningful category. Individual populations are assessed separately, and some, such as the Southern Residents of the northeastern Pacific, are listed as endangered under United States law.
Which animal is the fastest?
It depends on how speed is measured. Published top speeds are usually brief bursts, and several widely repeated figures, such as the sixty-eight miles per hour often credited to the sailfish, rest on a single old observation. The speed and body design guide explains how to read a speed figure, and each profile gives the best-supported maximum with a note on how it was observed.
Which animal is the largest?
Among the animals profiled here, the sperm whale is the largest predator, reaching about fifty feet, and the colossal and giant squids are the largest invertebrates. Length and weight records are often based on a few specimens, and the profiles say so. The catalog can be sorted by length or weight to compare the whole set.
How do I compare two animals?
Use the compare tool and pick any two profiles. It lays out the measurements side by side, shows which animal is larger, faster or deeper-diving on each trait, and explains the differences that matter. Some pairs have a written comparison that goes further, drawing out what the two animals illuminate about each other.
Are generated comparisons as detailed as the written ones?
No. A generated comparison is built from the same measurements and shows the data accurately, but it has no editorial interpretation. For that reason such pages are kept out of search results, while the written comparisons are published as articles in their own right.
Does the site rank animals or declare winners?
No. A shark and a whale do not meet in nature on equal terms, and a hypothetical fight between them says little about biology. Comparisons here are about how each animal is built and how it lives, with figures set next to each other so that the differences are visible.
Is the site a guide to safety around marine animals?
No. The content is educational reference material. It is not advice on swimming, diving, boating or encounters with wildlife, and readers should follow local authorities and trained guides for safety information.
How often is the content reviewed?
Each profile and guide carries a review date and is checked against its sources on a twelve-month cycle, sooner when a major assessment or study changes the picture. The updates page lists what has been added or changed, and the editorial policy describes the review process in detail.
How do I report an error?
Write to the editors through the contact page, naming the page and quoting the figure or sentence in question. Corrections are handled under the published corrections policy, and substantive changes are recorded on the updates page.
Why are some animals missing?
The catalog focuses on predators that illustrate the main ways of hunting in the ocean, from ambush and pursuit to filter-assisted and suction feeding. It is not an exhaustive list of marine life. Suggestions for species or comparisons worth adding are welcome through the contact page.